简便运算 1.5/7×1/4+1/4×2/7 2.100×(1/5+3/20+4/25) 3.1/5×50+50*4/5 4.2/9*8+2/9

问题描述:

简便运算 1.5/7×1/4+1/4×2/7 2.100×(1/5+3/20+4/25) 3.1/5×50+50*4/5 4.2/9*8+2/9

5/7×1/4+1/4×2/7=1/4(5/7+2/2)=1/4*1=1/4
100×(1/5+3/20+4/25)=100*1/5+100*3/20+100*4/25=20+15+16=51
1/5×50+50*4/5=50(1/5+4/5)=50*1=50
.2/9*8+2/9=2/9(8+1)=2/9*9=2
不懂可以追问欢迎
采纳

1.5/7×1/4+1/4×2/7=1/4x(5/7+2/7)=1/4x1=1/42.100×(1/5+3/20+4/25) =100x1/5+100x3/20+100x4/25=20+15+16=513.1/5×50+50*4/5 =50x(1/5+4/5)=50x1=504.2/9*8+2/9=2/9x(8+1)=2/9x9=2