(x-y)(x+y)ˇ8,则xˇ2yˇ7的系数是多少?

(x-y)(x+y)ˇ8,则xˇ2yˇ7的系数是多少? 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) (x-y)^2+7(x+y)-11(x-y)^2-8(x+y),先化简.再求值 （x-y)^2+7(x+y)-11(x-y)^2-8(X+Y)的计算过程 3(x-y)^2-7(x-y)+8(y-x)^2+6(y-x)合并同类项. 18(x+y)^8(x-y)^7÷[3(x+y)^3(x-y)^3]^2 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 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) (x-2y)(x+2y)-(x-2y)ˇ2,其中x=-2,y=二分之一 已知{2x+y=7,x+2y=8,则x-y=?x+y=? 已知方程组{2x+y=7,x+2y=8,则x-y=(),x+y=(). 化简y(x+y)+(x+y)(x-y)-x^2 因式分解:8(x-2y)-x(7x+y)+xy. 已知|5x-y-8|+(7y-x+2)=0则4x+6y 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3(x-y)-7(x--y)+2(y-x) (x-8y)(x+y)