计算:(1) (-4x^2-3y^3) (12x^2-9y^3)

计算（4x^2y-9y)/(2x+3) 计算:(-x-2y) * (3x-y) 计算:1/(x-y)-1/(x+y)-2y/(x^2+y^2)-4y^3/(x^4+y^4)-8x^7/(x^8+y^8 计算(x+y)(x+y)^2(-x-y)^3 (x-3y)(y+2x)-(4y-3x)(3x+4y)计算 计算【3(x-y)^2(x+y)^-2/4(x+y)^2(x-y)^-2】^-2 计算（2x-3y)(x+4y)-(3x+y)(x-2y) 计算1/6x-4y +1/6x+4y — 3x/4y^2-9x^2 计算:(2/3x√9x+6x√y/x)+(y√x/y-√1/x) 有这样一道题:"计算(2*x*x*x-3*x*x*y-2*x*y*y)-(x*x*x-2*x*y*y+y*y*y)+【- 计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2) 计算:[(2x - 3y)^2 - (x-y)(4x+2y)] / 2y