(3x+2y)(4x-5y)-12(x+y)(x-y)+7xy,其中x=2011,y=-1,

因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) 化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90) 5/4(x+y)(-x-y)^3*[-4/3(x-y)]*[-3/5(y-x)^2] 因式分解:12xy^2(y-x)+xy^3(x-y)+4x^2y(x-y) 12（x+y）^3（y-x）/【4（x+y）^2(x-y)】 5x^3y(x-y)^3-10x^4y^3(y-x)^2因式分解 5x^3y(x-y)^3-10x^4y^3(y-x)^2 (2x-y)(3x-4y)-2(x-y)(2x-5y)简便运算 5X^3Y(X-Y)-10X^4Y^3(Y-X)^2因式分解 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 （x-y）^3×（y-x）^4+（x-y）^2×（y-x）^5 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) 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 (1)x^2*x^8+x^13/x^3 (2)a^19/a^12/a^3 (3) (x-2y)^5/(2y-x)^3 (4)(x-y)^5/(x-y) (5)(x-y)^6/(y-x)^4 3(x-y)-2(x+y)-5(x-y)+4(x+y)+3(x-y) 化简合并同类项 5/12[-3/4(x-y)^3]*(x+y)^2*(-x-y)^3*5/6(y-x)^2