（x-2y）²+（2x-4y)(x+y)+(x+y)²

(2x-y)²-4(x-y)(x+2y) 化简：（2x-y)²-4(x-y)(x+y) （x-2y）²+（2x-4y)(x+y)+(x+y)² 求因式分解(x-y)²-2(x-y)³和（x+y）（x-y）-x（x-y） 若|x+2y-1|+y²+4y+4=0,求（2x-y）²-2（2x-y)(x+2y)+(x+2y)& (x-y)的四次方(x-y)-2(x-y)²(y-x）³等于? (3x-y)²-2x（4x-5y）-（x+2y）² 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 【（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 2.(x+y)²(x-y)²-(x-y)(x+y）(x²+y²) 因式分解 （1）.(x+y)(x+y-6)+9 （2）.x²-16y²-x-4y