Question

解方程组{(x+2)(y+1)=(x-5)(y-1) x(4+y)=-y(8-x),要过程

(x+2)(y+1) = (x-5)(y-1)
x(4+y) = -y(8-x)

Answer 1

解：
(x+2)(y+1) = (x-5)(y-1)
整理得
xy+x+2y+2=xy-x-5y+5
xy+x+2y-xy+x+5y=5-2
2x+7y=3 (1)
整理得
x(4+y) = -y(8-x)

4x+xy=-8y+xy
4x+xy-xy=-8y
4x=-8y
x=-2y (2)
把（2）带入（1）得
2*(-2y)+7y=3
-4y+7y=3
3y=3
y=1
把y=1带入（2）得
x=-2y
x=-2*1
x=-2
即
x=-2
y=1
希望你能看懂，祝你学习进步