-3(2x-y)-2(4x+1/2y)+2009
(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
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
(x+3y-4)(2x-y)
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2
[(2x+y)^2+(y+2x)(y-2x)-2y(4x-y)]/4y,其中x=1/2,y=1/3
(2x+y)(2x-3y)+x(2y+y) 2a(x-y)-4b(x-y)
1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [(x+y)(x-y)-(x-y)^2+2y(x-y
因式分解 (1)6(x-y)^3-3y(y-x)^2 (2)x(x-y)(a-b)-y(y-x)(