解方程组x+2xy+y²=9 （x-y)²-3（x-y)=2=0

解方程组x+2xy+y²=9 （x-y)²-3（x-y)=2=0
解方程组x+2xy+y²=9 （x-y)²-3（x-y)=2=0

解方程组x+2xy+y²=9 （x-y)²-3（x-y)=2=0
看不懂你的题.是几个等式?最后到底是等于几?

(x+y)²=9 x+y=3
(x-y-2)(x-y-1)=0 x-y-2=0 x-y-1=0
x1=2 y1=1
x2=2.5 y2=0.5

x² 2xy y²=9
(x y)²=9
x y=±3
(x-y)²-3(x-y) 2=0
(x-y-1)(x-y-2)=0
x-y-1=0 x-y-2=0
x-y=1 x-y=2
{x y=3 x-y=1}解得x=2 y=1
{x y=3 x-y=2 }解得 x=5/2 y=1/2
{x y=-3 x-y=1}解得x=-1 y=-2
{x y=-3 x-y=2}解得x=-1/2 y=-5/2