(2x/3y²)²÷(-x/y)³

急![(3x+y)²-3(3x-y)(x+y)-(x-3y)(x+3y)]÷(2xy) 化简x-y分之x + x³-2x²y+xy²分之y³ ÷ y²-x&# [x（x²y²-xy）-y（x²-x³y）]÷3x²y 【x(x²y²-xy)-y(x²-x³y)】÷3x²y 因式分解：[x（x²y²-xy）-y（x²-x³y）]÷3x²y 求因式分解(x-y)²-2(x-y)³和（x+y）（x-y）-x（x-y） 化简后求值 [(x-2y)²+(x-2y)(x-2y)-2x(2x-y)]÷2x 其中x=2 y=3 计算6x³y^6÷(1/2)y³÷(-3x²y)-(12x^4y^6-8x²y^ 计算 [12(x+y)³(y-x)]³÷[4(x+y)²（x-y)]² 合并同类项：-6x²y-x+5x²y-2x+x³y+3x (x-y)的四次方(x-y)-2(x-y)²(y-x）³等于? 若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值