先化简再求值 已知x(x-1)-(x²-y0=-2,求x²+y²÷2-xy的值先化简再求值 已知x(x-1)-(x²-y0=-2,求x²+y²÷2-xy的值

先化简再求值 已知x(x-1)-(x²-y0=-2,求x²+y²÷2-xy的值先化简再求值 已知x(x-1)-(x²-y0=-2,求x²+y²÷2-xy的值
先化简再求值 已知x(x-1)-(x²-y0=-2,求x²+y²÷2-xy的值
先化简再求值 已知x(x-1)-(x²-y0=-2,求x²+y²÷2-xy的值

先化简再求值 已知x(x-1)-(x²-y0=-2,求x²+y²÷2-xy的值先化简再求值 已知x(x-1)-(x²-y0=-2,求x²+y²÷2-xy的值
即想²-x-x²+y=-2
-x+y=-2
x-y=2
所以原式=(x²+y²-2xy)/2
=(x-y)²/2
=4/2
=2