42.5×6.28-4.25×2.8简便算法
问题描述:
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?
答
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还有一题没回答呢50.9-7.3×6.950.9-7.3×6.9
=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有点太复杂,还是采纳吧