解方程组4(x+1)-6(y-1)=20 2(x+1)+7(y-1）=20

4(x+1)-6(y-1)=20 ---(1)
2(x+1)+7(y-1)=20 ---(2)
(2)X2
4(x+1)+14(y-1)=40 ---(3)
(3)-(1)
20(y-1)=20
y=2
将y=2带入（1）,得
4(x+1)-6(y-1)=20
x=11/2