(2x-3y)^13÷[(2x-3y)^3]^2 其中x等于2,y等于1.先化简,再求值.

化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x (x+y)-(x-y)^3÷(x-y)(x+y)×2y化简e , x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² [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 x(x-y)2-(y-x)3 [2/3x-2/x+y(x+y/3x-x-y)]/x-y/x 化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/(x+y)/x 计算2/3x-2/x+y(x+y/3x-x-y)/x-y/x 计算:y×(y/x)^3÷[-(x^2)/y]^-2 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 [(2x+y)(x-3y)+y(x+3y)]÷(2x)计算, [(x-2y)²+(x+y)(3x-y)-3y²]÷2x化简。 18(x+y)^8(x-y)^7÷[3(x+y)^3(x-y)^3]^2 [3(x-y)^3-(y-x)^2+x-y]÷(x-y) 多项式除以单项式 [12(x+y)^3+3(x+y)(x-y)^2]÷6(x+y) 4x-3y/x-2y÷6y-8x/y-2x [(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y)