解方程组:1、6(x-y)-2(x-y)=14 2、3(x-y)+(x+y)+5 怎么解

问题描述:

解方程组:1、6(x-y)-2(x-y)=14 2、3(x-y)+(x+y)+5 怎么解
=5

6(x-y)-2(x-y)=14
3(x-y)+(x+y)=5
6x-6y-2x+2y=14
3x-3y+x+y=5
2x-2y=7 (1)
4x-2y=5 (2)
(1)-(2)得
-2x=2
x=-1
y=-9/2