(5x^4-10x^3y+25x^2y^2)/(-5x^2)

1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [（x+y)(x-y)-(x-y)^2+2y(x-y （x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3) 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 数学(x-y)^5*(y-x)^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 化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90) (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (2X-3y)-(5x-y) 3(x-y)-2(x+y)-5(x-y)+4(x+y)+3(x-y) 化简合并同类项 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(