(-2y/3x)^-2÷5y/6x÷(-3x^2/y)^3

[2(x-y)^5-8(x-y)^2(x+y)+6y(x-y)^2]÷2(x-y)^2[2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2]÷2(x-y)^2 化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x 计算：(x-y)^7÷(y-x)^6+(-x-y)^3÷(x+y)^2 计算(x-y)^7÷(y-x)^6+9-x-y)^3÷(x+y)^2 4x-3y/x-2y÷6y-8x/y-2x [12(x+y)^3+3(x+y)(x-y)^2]÷6(x+y) 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) (-2y/3x)^-2÷5y/6x÷(-3x^2/y)^3 (x+y)-(x-y)^3÷(x-y)(x+y)×2y化简e , 2x²/3y²×5y/6x÷10y/21x^2 x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² (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 6x^3y^2÷(-y/x)*x/y^2÷x^2 计算：(x+2y)(3x-5y)-(6x的四次方y²-2x²y²）÷（2x²y²） ((x+2y)x^2+（x-y）（3x-y)-5y^2）÷2x 1.(x^3-x^2-4x+1)/(x^2-3x+2)-(x^3-2x^2-9x+21)/（x^2-5x+6）+（x^2-3x+8）/（x^2-4x+3）2.{(x^2)/（x-y)}*{y/(x+y)}-{(x^4y)/(x^4-y^4)}÷{（x^2/x^2+y^2）^2} [(x+2y)^2-(x-y)(x+2y)-5y^2]÷(2y)