(3x-y)(3x+y)+y(x+y);(a+1/2b)(a-1/2b)-(3a-2b)(3a+2b)快点,

(3x-y)(3y+x)-(x-y)(x+y) x(x-y)2-(y-x)3 （y-x)+x(x-y)^3-(y-x)^4 因式分解 计算 3x+4y/x-y+3y/y-x-4x/x-y 3x+4y/x-y +3y/y-x -4x/x-y [(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y) x(4y-x)(x-3y)+y(3y-x)(x-4y)因式分解 计算：x+2y/x-y+2x/y-x-3y/x-y 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x [2/3x-2/x+y(x+y/3x-x-y)]/x-y/x 化简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 推倒公式:(x+y)(x*x-3x+y*y)=x*x*x+y*y*y怎么做. {(x,y) |x|+|y| x>y?x:y