开始时间 : 2018-11-23结束时间 : 2018-11-28

步骤描述： <p style="text-align:center;line-height:30px;text-autospace:none"><strong><span style="font-size:21px;font-family:NEU-BZ">第4课时　利用去分母解一元一次方程</span></strong></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学目标</span></strong><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">能够熟练地解含有分数系数的方程</span><span style="font-size: 16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">进一步提高列一元一次方程解决实际问题的能力</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学重点</span></strong><strong><span style="font-size:16px">:</span></strong></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">分析实际问题的方法</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">去分母时符号的处理</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学难点</span></strong><strong><span style="font-size:16px">:</span></strong><span style="font-size:16px;font-family:宋体">分析实际问题中的数量关系、列方程</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学过程</span></strong><strong><span style="font-size:16px">:</span></strong></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">一、创设情境</span></strong><strong><span style="font-size:16px">,</span></strong><strong><span style="font-size:16px;font-family: 宋体">提出问题</span></strong></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">出示课本</span><span style="font-size:16px">P95</span><span style="font-size:16px;font-family: 宋体">问题</span><span style="font-size:16px">2:</span></p><p style="line-height:33px"><span style="font-size:16px">(1)</span><span style="font-size:16px;font-family:宋体">小组合作探究</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">列出方程</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">(2)x+x+x+x=33</span><span style="font-size: 16px;font-family:宋体">的解法有几种方法</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">每种解法的依据是什么</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">解法</span><span style="font-size:16px">1:</span><span style="font-size:16px;font-family: 宋体">将方程左边通分得</span><span style="font-size:16px">:x=33,</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">即</span><span style="font-size:16px">x=33,x=33</span><span style="font-size:16px;font-family:宋体">×</span><span style="font-size:16px">,x=.</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">解法</span><span style="font-size:16px">2:</span><span style="font-size:16px;font-family: 宋体">将方程两边都乘</span><span style="font-size:16px">42</span><span style="font-size:16px;font-family:宋体">去掉分母</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">得</span><span style="font-size:16px">:28x+21x+6x+42x=1386,x=.</span></p><p style="line-height:33px"><span style="font-size:16px">(3)</span><span style="font-size:16px;font-family:宋体">比较两种解法</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">二、合作探究</span></strong></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">解方程</span><span style="font-size:16px">:-2=-.</span></p><p style="line-height:33px"><span style="font-size:16px">(1)</span><span style="font-size:16px;font-family:宋体">如何去分母</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">依据是什么</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">(2)</span><span style="font-size:16px;font-family:宋体">方程两边都乘</span><span style="font-size:16px">10</span><span style="font-size:16px;font-family:宋体">的过程中有哪些注意事项</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">(3)</span><span style="font-size:16px;font-family:宋体">交流解题过程</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">指出问题</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">并强调注意事项</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">(4)</span><span style="font-size:16px;font-family:宋体">解一元一次方程的一般步骤</span><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">去分母</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family: 宋体">去括号</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family:宋体">移项</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family:宋体">合并同类项</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family: 宋体">系数化</span><span style="font-size:16px">1.</span></p><p style="line-height:33px"><span style="font-size:16px">&nbsp;(1)</span><span style="font-size:16px;font-family:宋体">为庆祝校运会开幕</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">七年级</span><span style="font-size:16px">(1)</span><span style="font-size:16px;font-family:宋体">班学生接受了制作校旗的任务</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family:宋体">原计划一半同学参加制作</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">每天制作</span><span style="font-size:16px">40</span><span style="font-size:16px;font-family:宋体">面</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family:宋体">而实际上</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">在完成了三分之一以后</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">全班同学一起参加制作</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">结果比原计划提前一天半完成任务</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family:宋体">假设每人的制作效率相同</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">问共制作小旗多少面</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">&nbsp;(3)</span><span style="font-size:16px;font-family:宋体">将上述两题加以比较</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">有否相通之处</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">可否一题多解</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">并探究设未知数的技巧性</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">三、课堂练习</span></strong></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">完成课本</span><span style="font-size:16px">P97</span><span style="font-size:16px;font-family:宋体">例</span><span style="font-size:16px">3,</span><span style="font-size:16px;font-family: 宋体">解下列方程</span><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px">(1)-1=2+;</span></p><p style="line-height:33px"><span style="font-size:16px">(2)3x+=3-.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">四、综合应用</span></strong><strong><span style="font-size:16px">,</span></strong><strong><span style="font-size:16px;font-family: 宋体">巩固提高</span></strong></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">完成课本</span><span style="font-size:16px">P98</span><span style="font-size:16px;font-family:宋体">练习</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">解方程</span><span style="font-size:16px">:(1)-=2;</span></p><p style="line-height:33px"><span style="font-size:16px">(2)-y+5=-.</span></p><p style="line-height:33px"><span style="font-size:16px">(3)=+1;</span></p><p style="line-height:33px"><span style="font-size:16px">(4){[x(+3)+5]+7}=1.</span></p><p style="line-height:33px"><span style="font-size:16px">3.</span><span style="font-size:16px;font-family:宋体">一部稿件</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">甲打字员单独打</span><span style="font-size:16px">20</span><span style="font-size:16px;font-family: 宋体">小时可以完成</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">甲、乙两打字员合打</span><span style="font-size:16px">,12</span><span style="font-size:16px;font-family:宋体">小时可以完成</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family: 宋体">现由两人合打</span><span style="font-size:16px">7</span><span style="font-size:16px;font-family:宋体">小时</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">余下部分由乙完成</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">还需多少小时</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">五、课时小结</span></strong></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">可通过以下问题引导学生小结</span><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">去分母解一元一次方程时要注意什么</span><span style="font-size: 16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">去分母解一元一次方程时</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">在方程两边同时乘以各分母最小公倍数的目的是什么</span><span style="font-size:16px">?</span></p><p><br/></p>

开始时间 : 2018-11-23结束时间 : 2018-11-28

步骤描述： <p style="text-align:center;line-height:30px;text-autospace:none"><strong><span style="font-size:21px;font-family:NEU-BZ">第4课时　利用去分母解一元一次方程</span></strong></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学目标</span></strong><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">能够熟练地解含有分数系数的方程</span><span style="font-size: 16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">进一步提高列一元一次方程解决实际问题的能力</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学重点</span></strong><strong><span style="font-size:16px">:</span></strong></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">分析实际问题的方法</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">去分母时符号的处理</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学难点</span></strong><strong><span style="font-size:16px">:</span></strong><span style="font-size:16px;font-family:宋体">分析实际问题中的数量关系、列方程</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学过程</span></strong><strong><span style="font-size:16px">:</span></strong></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">一、创设情境</span></strong><strong><span style="font-size:16px">,</span></strong><strong><span style="font-size:16px;font-family: 宋体">提出问题</span></strong></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">出示课本</span><span style="font-size:16px">P95</span><span style="font-size:16px;font-family: 宋体">问题</span><span style="font-size:16px">2:</span></p><p style="line-height:33px"><span style="font-size:16px">(1)</span><span style="font-size:16px;font-family:宋体">小组合作探究</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">列出方程</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">(2)x+x+x+x=33</span><span style="font-size: 16px;font-family:宋体">的解法有几种方法</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">每种解法的依据是什么</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">解法</span><span style="font-size:16px">1:</span><span style="font-size:16px;font-family: 宋体">将方程左边通分得</span><span style="font-size:16px">:x=33,</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">即</span><span style="font-size:16px">x=33,x=33</span><span style="font-size:16px;font-family:宋体">×</span><span style="font-size:16px">,x=.</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">解法</span><span style="font-size:16px">2:</span><span style="font-size:16px;font-family: 宋体">将方程两边都乘</span><span style="font-size:16px">42</span><span style="font-size:16px;font-family:宋体">去掉分母</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">得</span><span style="font-size:16px">:28x+21x+6x+42x=1386,x=.</span></p><p style="line-height:33px"><span style="font-size:16px">(3)</span><span style="font-size:16px;font-family:宋体">比较两种解法</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">二、合作探究</span></strong></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">解方程</span><span style="font-size:16px">:-2=-.</span></p><p style="line-height:33px"><span style="font-size:16px">(1)</span><span style="font-size:16px;font-family:宋体">如何去分母</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">依据是什么</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">(2)</span><span style="font-size:16px;font-family:宋体">方程两边都乘</span><span style="font-size:16px">10</span><span style="font-size:16px;font-family:宋体">的过程中有哪些注意事项</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">(3)</span><span style="font-size:16px;font-family:宋体">交流解题过程</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">指出问题</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">并强调注意事项</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">(4)</span><span style="font-size:16px;font-family:宋体">解一元一次方程的一般步骤</span><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">去分母</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family: 宋体">去括号</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family:宋体">移项</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family:宋体">合并同类项</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family: 宋体">系数化</span><span style="font-size:16px">1.</span></p><p style="line-height:33px"><span style="font-size:16px">&nbsp;(1)</span><span style="font-size:16px;font-family:宋体">为庆祝校运会开幕</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">七年级</span><span style="font-size:16px">(1)</span><span style="font-size:16px;font-family:宋体">班学生接受了制作校旗的任务</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family:宋体">原计划一半同学参加制作</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">每天制作</span><span style="font-size:16px">40</span><span style="font-size:16px;font-family:宋体">面</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family:宋体">而实际上</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">在完成了三分之一以后</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">全班同学一起参加制作</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">结果比原计划提前一天半完成任务</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family:宋体">假设每人的制作效率相同</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">问共制作小旗多少面</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">&nbsp;(3)</span><span style="font-size:16px;font-family:宋体">将上述两题加以比较</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">有否相通之处</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">可否一题多解</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">并探究设未知数的技巧性</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">三、课堂练习</span></strong></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">完成课本</span><span style="font-size:16px">P97</span><span style="font-size:16px;font-family:宋体">例</span><span style="font-size:16px">3,</span><span style="font-size:16px;font-family: 宋体">解下列方程</span><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px">(1)-1=2+;</span></p><p style="line-height:33px"><span style="font-size:16px">(2)3x+=3-.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">四、综合应用</span></strong><strong><span style="font-size:16px">,</span></strong><strong><span style="font-size:16px;font-family: 宋体">巩固提高</span></strong></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">完成课本</span><span style="font-size:16px">P98</span><span style="font-size:16px;font-family:宋体">练习</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">解方程</span><span style="font-size:16px">:(1)-=2;</span></p><p style="line-height:33px"><span style="font-size:16px">(2)-y+5=-.</span></p><p style="line-height:33px"><span style="font-size:16px">(3)=+1;</span></p><p style="line-height:33px"><span style="font-size:16px">(4){[x(+3)+5]+7}=1.</span></p><p style="line-height:33px"><span style="font-size:16px">3.</span><span style="font-size:16px;font-family:宋体">一部稿件</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">甲打字员单独打</span><span style="font-size:16px">20</span><span style="font-size:16px;font-family: 宋体">小时可以完成</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">甲、乙两打字员合打</span><span style="font-size:16px">,12</span><span style="font-size:16px;font-family:宋体">小时可以完成</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family: 宋体">现由两人合打</span><span style="font-size:16px">7</span><span style="font-size:16px;font-family:宋体">小时</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">余下部分由乙完成</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">还需多少小时</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">五、课时小结</span></strong></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">可通过以下问题引导学生小结</span><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">去分母解一元一次方程时要注意什么</span><span style="font-size: 16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">去分母解一元一次方程时</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">在方程两边同时乘以各分母最小公倍数的目的是什么</span><span style="font-size:16px">?</span></p><p><br/></p>

开始时间 : 2018-11-23结束时间 : 2018-11-28

步骤描述： <p style="text-align:center;line-height:30px;text-autospace:none"><strong><span style="font-size:21px;font-family:NEU-BZ">第4课时　利用去分母解一元一次方程</span></strong></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学目标</span></strong><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">能够熟练地解含有分数系数的方程</span><span style="font-size: 16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">进一步提高列一元一次方程解决实际问题的能力</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学重点</span></strong><strong><span style="font-size:16px">:</span></strong></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">分析实际问题的方法</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">去分母时符号的处理</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学难点</span></strong><strong><span style="font-size:16px">:</span></strong><span style="font-size:16px;font-family:宋体">分析实际问题中的数量关系、列方程</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">教学过程</span></strong><strong><span style="font-size:16px">:</span></strong></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">一、创设情境</span></strong><strong><span style="font-size:16px">,</span></strong><strong><span style="font-size:16px;font-family: 宋体">提出问题</span></strong></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">出示课本</span><span style="font-size:16px">P95</span><span style="font-size:16px;font-family: 宋体">问题</span><span style="font-size:16px">2:</span></p><p style="line-height:33px"><span style="font-size:16px">(1)</span><span style="font-size:16px;font-family:宋体">小组合作探究</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">列出方程</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">(2)x+x+x+x=33</span><span style="font-size: 16px;font-family:宋体">的解法有几种方法</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">每种解法的依据是什么</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">解法</span><span style="font-size:16px">1:</span><span style="font-size:16px;font-family: 宋体">将方程左边通分得</span><span style="font-size:16px">:x=33,</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">即</span><span style="font-size:16px">x=33,x=33</span><span style="font-size:16px;font-family:宋体">×</span><span style="font-size:16px">,x=.</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">解法</span><span style="font-size:16px">2:</span><span style="font-size:16px;font-family: 宋体">将方程两边都乘</span><span style="font-size:16px">42</span><span style="font-size:16px;font-family:宋体">去掉分母</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">得</span><span style="font-size:16px">:28x+21x+6x+42x=1386,x=.</span></p><p style="line-height:33px"><span style="font-size:16px">(3)</span><span style="font-size:16px;font-family:宋体">比较两种解法</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">二、合作探究</span></strong></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">解方程</span><span style="font-size:16px">:-2=-.</span></p><p style="line-height:33px"><span style="font-size:16px">(1)</span><span style="font-size:16px;font-family:宋体">如何去分母</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">依据是什么</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">(2)</span><span style="font-size:16px;font-family:宋体">方程两边都乘</span><span style="font-size:16px">10</span><span style="font-size:16px;font-family:宋体">的过程中有哪些注意事项</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">(3)</span><span style="font-size:16px;font-family:宋体">交流解题过程</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">指出问题</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">并强调注意事项</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">(4)</span><span style="font-size:16px;font-family:宋体">解一元一次方程的一般步骤</span><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">去分母</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family: 宋体">去括号</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family:宋体">移项</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family:宋体">合并同类项</span><span style="font-size:16px">—</span><span style="font-size:16px;font-family: 宋体">系数化</span><span style="font-size:16px">1.</span></p><p style="line-height:33px"><span style="font-size:16px">&nbsp;(1)</span><span style="font-size:16px;font-family:宋体">为庆祝校运会开幕</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">七年级</span><span style="font-size:16px">(1)</span><span style="font-size:16px;font-family:宋体">班学生接受了制作校旗的任务</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family:宋体">原计划一半同学参加制作</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">每天制作</span><span style="font-size:16px">40</span><span style="font-size:16px;font-family:宋体">面</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family:宋体">而实际上</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">在完成了三分之一以后</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">全班同学一起参加制作</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">结果比原计划提前一天半完成任务</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family:宋体">假设每人的制作效率相同</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">问共制作小旗多少面</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">&nbsp;(3)</span><span style="font-size:16px;font-family:宋体">将上述两题加以比较</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">有否相通之处</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">可否一题多解</span><span style="font-size:16px">?</span><span style="font-size:16px;font-family:宋体">并探究设未知数的技巧性</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">三、课堂练习</span></strong></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">完成课本</span><span style="font-size:16px">P97</span><span style="font-size:16px;font-family:宋体">例</span><span style="font-size:16px">3,</span><span style="font-size:16px;font-family: 宋体">解下列方程</span><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px">(1)-1=2+;</span></p><p style="line-height:33px"><span style="font-size:16px">(2)3x+=3-.</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">四、综合应用</span></strong><strong><span style="font-size:16px">,</span></strong><strong><span style="font-size:16px;font-family: 宋体">巩固提高</span></strong></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">完成课本</span><span style="font-size:16px">P98</span><span style="font-size:16px;font-family:宋体">练习</span><span style="font-size:16px">.</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">解方程</span><span style="font-size:16px">:(1)-=2;</span></p><p style="line-height:33px"><span style="font-size:16px">(2)-y+5=-.</span></p><p style="line-height:33px"><span style="font-size:16px">(3)=+1;</span></p><p style="line-height:33px"><span style="font-size:16px">(4){[x(+3)+5]+7}=1.</span></p><p style="line-height:33px"><span style="font-size:16px">3.</span><span style="font-size:16px;font-family:宋体">一部稿件</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">甲打字员单独打</span><span style="font-size:16px">20</span><span style="font-size:16px;font-family: 宋体">小时可以完成</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">甲、乙两打字员合打</span><span style="font-size:16px">,12</span><span style="font-size:16px;font-family:宋体">小时可以完成</span><span style="font-size:16px">.</span><span style="font-size:16px;font-family: 宋体">现由两人合打</span><span style="font-size:16px">7</span><span style="font-size:16px;font-family:宋体">小时</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">余下部分由乙完成</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family: 宋体">还需多少小时</span><span style="font-size:16px">?</span></p><p style="line-height:33px"><strong><span style="font-size:16px;font-family: 宋体">五、课时小结</span></strong></p><p style="line-height:33px"><span style="font-size:16px;font-family:宋体">可通过以下问题引导学生小结</span><span style="font-size:16px">:</span></p><p style="line-height:33px"><span style="font-size:16px">1.</span><span style="font-size:16px;font-family:宋体">去分母解一元一次方程时要注意什么</span><span style="font-size: 16px">?</span></p><p style="line-height:33px"><span style="font-size:16px">2.</span><span style="font-size:16px;font-family:宋体">去分母解一元一次方程时</span><span style="font-size:16px">,</span><span style="font-size:16px;font-family:宋体">在方程两边同时乘以各分母最小公倍数的目的是什么</span><span style="font-size:16px">?</span></p><p><br/></p>