(x²+y²)(x² +y²+1)=20,求x²+y²
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
求因式分解(x-y)²-2(x-y)³和(x+y)(x-y)-x(x-y)
2.(x+y)²(x-y)²-(x-y)(x+y)(x²+y²)
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
(1)已知x+y=6,x²-y²=5,求x-y的值(2)若x+y=3,x²+y²
因式分解 -5x³y(x-y)³+20y【x²(y-x)】²
已知x+y=1,xy=-二分之一,求x(x+y)(x-y)-x(x+y)²
【(X²+Y²)-(X-Y)²+2Y(X-Y)】/4Y=1,求4X/4X²-Y&
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
x²+y²-6x+8y+25=0求(x-y)-²
x+y=3,x²+y²=5,求(x-y)^2014