(-3x^4y^2+2x^2y-1/4x^3y^2)/(-2x)^2
x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2
(x+3y-4)(2x-y)
(x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3)
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
(2x+y)(2x-3y)+x(2y+y) 2a(x-y)-4b(x-y)
1、x(x-y)(x+y)-x(x+y)^2
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
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
计算【3(x-y)^2(x+y)^-2/4(x+y)^2(x-y)^-2】^-2
(2x-y)(2x+y)-2(3x-4y)(4y+3x)
计算(2x-3y)(x+4y)-(3x+y)(x-2y)