（4x-7y)-(3x+2y)

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) 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) 先化简再求值{(x-y)(x+y)-(x+y)(x-2y)}/y 其中xy的值是代数式{(3x-2y-7)^2+|2x+3y先化简再求值{(x-y)(x+y)-(x+y)(x-2y)}/y 其中x和y的值是代数式{(3x-2y-7)^2+|2x+3y+4|}^0无意义 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (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) 已知（x+y）2 =2,(x-y)3 =3,求(x+y)7(x-y)2(x+y)3(y-x)4 的值 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 将(x-y)看成一个整体,将3(x-y)²-4(x-y)+7(x-y)-6(y-x)²-2(y-x)合并同类项. x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² (2x+y)(2x-3y)+x(2y+y) 2a(x-y)-4b(x-y) 把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)= 3(x-y)把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)=3(x-y)²-4(x-y)+7(x-y)-6(x-y)²= x-4y分之3x + 4y-x分之x+y - x*x-4y分之7y （4x-7y)-(3x+2y) (2x-7y)(3x+4y-1) (2x-7y)(3x+4y-1)