(x-y)^3÷(y-x)=?算死算不出?誰知道?謝謝了..

化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 推倒公式:(x+y)(x*x-3x+y*y)=x*x*x+y*y*y怎么做. (x+y)(x-y)+(x-y)^2-(6x^2×y÷2y-2xy^2÷2y)其中x=-3,y=1/3 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y 先化简再求值:(x+y)(x-y)+(x^2-2xy+y^2)-(x^2y)^3÷(x^2y)^2,其中x=1,y=2. 先化简,后求值:[(x-y)²+(x+y)(x-y)]÷2x,其中x=3,y=1.5 (x+y)-(x-y)^3÷(x-y)(x+y)×2y化简e , (x+y)(x-y)+(x-y)平方-(x-y)(3x-y) 其中x=-2 y=3分之一 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 化简 x-y/(y-x)^3= (x+y)(2x-3y)=? 化简后求值 [(x-2y)²+(x-2y)(x-2y)-2x(2x-y)]÷2x 其中x=2 y=3 x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x²