4/5+8*0.45简便计算

Question

如题所述

Answer 1

4/5+8*0.45
=0.8+0.8x4.5
=(1+4.5)x0.8
=5.5x0.8
=4.4追问

为什么1+4.5呢？1哪里来的

追答

4/5+8*0.45
=0.8+0.8x4.5
=1x0.8+0.8x4.5
=(1+4.5)x0.8
=5.5x0.8
=4.4

祝学习进步，望采纳~~

追问

那个1是根据题外加的，对吗？

追答

不是
0.8=0.8x1
也算是题外加的吧

本回答被提问者采纳

Answer 2

4/5+8*0.45
=0.8+0.8*4.5
=0.8*(1+4.5)
=0.8*5.5
=4/5 *5.5
=4*1.1
=4.4

Answer 3

4/5+8*0.45
=4/5+8*9/20
=16/20+72/20
=（16+72）/20
=88/20
=4.4