4x-2*（100-x）=80

题目

4x-2*（100-x）=80
这个方程怎么解,
要是
2乘（100—x）-4x=80

答案

(1)
4x - 200 + 2x = 80
6x = 80 + 200
6x = 280
x = 140 / 3
(2)
200 - 2x - 4x = 80
-6x = -120
x = 20