-3*(2x-y)-2*(4x-½y)+2009的多少,

(x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² (x+3y-4)(2x-y) 计算（2x-3y)(x+4y)-(3x+y)(x-2y)（2x-3y)(x+4y)-(3x+y)(x-2y) 因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) x(x-y)2-(y-x)3 (2x+y)(2x-3y)+x(2y+y) 2a(x-y)-4b(x-y) [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 化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x (2x-y)(2x+y)-2(3x-4y)(4y+3x) x^3+2x^2y-4x-8y 2x-{-3y+[4x-(2y-x)]} x^4+x^3y+x^2*y^2+y^3x+y^4分解因式 4x*3-4x*2y-(x-y)因式分解 (3x-y)(y+3x)-2(4x-3y)(4x+3y) 化简：2x-{-3y+[4x-(3x-y]}