5x+7y-3x

用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+. (3x-4y)(5x-4y)-(7x-8y)(6y-5x) 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 7x+[-3x-3（x-2y）]-[5x-（2x-y）] 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 5x+7y-3x (y-x)(x-y)^3(y-x)^5怎么算 数学(x-y)^5*(y-x)^3*(x-y)^2 (5x^3-7x^3y+3x^2y)+2x^3-(－7x^3y+3x^2y+7x^3) y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)