6x-5y=11 (1)
-4x-4y=7 (2)
(2)式两边同时除以-4
x+y=-7/4 (3)
(3)式两边同时乘以5
5x+5y=-35/4 (4)
(1)+(4)
11x=11-35/4
x=9/44 (5)
(3)-(5)
y=-23/22