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42.5×6.28-4.25×2.8简便算法

来源:学生作业帮 编辑:拍题作业网作业帮 分类:数学作业 时间:2024/04/28 22:54:37
42.5×6.28-4.25×2.8简便算法
50.9-7.3×6.9
42.5×6.28-4.25×2.8简便的计算方法?
42.5×6.28-4.25×2.8=4.25×62.8-4.25×2.8=4.25×(62.8-2.8)=4.25×60=255
再问: 还有一题没回答呢50.9-7.3×6.9
再答: 50.9-7.3×6.9
=60-0.1-7.3×(7-0.1)
=60-0.1-7.3×7+7.3×0.1
=60-7.3×7+0.1×(7.3-1)
=60-51.1+0.63
=8.9+0.63
=9.53
再问: 有点太复杂,还是采纳吧