3x-3y-7x-5y

(3x-4y)(5x-4y)-(7x-8y)(6y-5x) 化简:3(x-y)²-7(x-y)+ 2(x-y)²+5(x-y) 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+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 化简3(x-y)-7(x--y)+2(y-x) 化简:5(x-y)+2(x+y)-3(x-y) (y-x)(x-y)^3(y-x)^5怎么算 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (3x-y)(3y+x)-(x-y)(x+y) 5(x-y)³-3（x-y）²+7(x-y)-5(x-y)³+（x-y）²-5（x-y）,其中,x-y=1/3.5(x-y)³-3（x-y）²+7(x-y)-5(x-y)³+（x-y）²-5（x-y）,其中,x-y=1/3先化简,再求值； (3x+y)(3x-7y) -（x+y)+(3x-7y) (2x-3y)-(5x-y) (2X-3y)-(5x-y) (2x-5y)(3x+y) 计算(x+y)(x-y)(x+y)3次方(x-y)5次方计算(x+y)×(x-y)×(x+y)3次方×(x-y)5次方 因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y)