解方程. x-2/5x=21 24-120%x=18 x-4×2/3=1/5.

问题描述:

解方程.

x-
2
5
x=21
24-120%x=18 x-4×
2
3
=
1
5

(1)x-25x=21,       35x÷35=21÷35,            x=35;(2)24-120%x=18,24-120%x+120%x=18+120%x,  &nbs...