Question

2.5*31.36+17.14*2.5简便运算？

Answer 1

2.5×31.36+17.14×2.5
=2.5×（31.36+17.14）
=2.5×48.5
=2.5×（48+0.5）
=2.5×48+2.5×0.5
=2.5×（4×12）+（2+0.5）×0.5
=（2.5×4）×12+2×0.5+0.5×0.5
=10×12+1+0.25
=120+1+0.25
=121.25

Answer 2

这道题的简便计算，可以把2.5提到括号外，然后先做加法。最后做乘法就会比较简单。
2.5×31.36+17.14×2.5
=2.5*(31.36+17.14)
=2.5*49
=2.5*(50-1)
=2.5*50+2.5*1
=125+2.5
=127.5。
通过计算最后答案等于127.5。

Answer 3

解：2.5×31.36+17.14×2.5
=2.5×（31.36+17.14）
=2.5×48.5
=2.5×（50-1-0.5）
=2.5×50-2.5×1-2.5×0.5
=125-2.5-1.25
=122.5-1.25
= 121.25

Answer 4

2.5*31.36+17.14*2.5
=2.5*(31.36+17.14)
=2.5*48.5
=121.25

Answer 5

原式=2.5*(31.36+17.14)
=2.5*48.5
=2.5*50-2.5*1.5
=125-1.25-7.5
=125-8.75
=116.25