已知(x-1)²+丨y+2丨=0 求代数式2x²+(-x²-2xy+2y²)-2(x²-xy+2y²)的值已知(x-1)²+丨y+2丨=0 求代数式2x²+(-x²-2xy+2y²)-2(x²-xy+2y²)的值

已知(x-1)²+丨y+2丨=0 求代数式2x²+(-x²-2xy+2y²)-2(x²-xy+2y²)的值已知(x-1)²+丨y+2丨=0 求代数式2x²+(-x²-2xy+2y²)-2(x²-xy+2y²)的值
已知(x-1)²+丨y+2丨=0 求代数式2x²+(-x²-2xy+2y²)-2(x²-xy+2y²)的值
已知(x-1)²+丨y+2丨=0 求代数式2x²+(-x²-2xy+2y²)-2(x²-xy+2y²)的值

已知(x-1)²+丨y+2丨=0 求代数式2x²+(-x²-2xy+2y²)-2(x²-xy+2y²)的值已知(x-1)²+丨y+2丨=0 求代数式2x²+(-x²-2xy+2y²)-2(x²-xy+2y²)的值
(x-1)²+丨y+2丨=0
所以x-1=0,y+2=0
x=1,y=-2
所以原式=2x²-x²-2xy+2y²-2x²+2xy-4y²
=-x²-2y²
=-1-8
=-9