(3x+7y)(-3x-7y)

(3x+y)(3x-7y) x-4y分之3x + 4y-x分之x+y - x*x-4y分之7y (-3x+7y)(-7y-3x)-(x-3y)(2x+3y) 2(y-x)的平方-7(x-y)+6(x-y)-3(y-x)的平方 化简 3(X-Y)²-4(X-Y)+7(X-Y)-6(X-Y)² 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 因式分解：(x-y)(3x-7y)²-4(x-y)(x+y)² (3x-4y)(5x-4y)-(7x-8y)(6y-5x) 计算：(x-y)^7÷(y-x)^6+(-x-y)^3÷(x+y)^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^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8 1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)