证明(5xy-3x^2+3)+2(y^2-xy+x^2)-(3xy+2y-x^2+3)的值与X无关

证明(5xy-3x^2+3)+2(y^2-xy+x^2)-(3xy+2y-x^2+3)的值与X无关 证明：代数式[(x+y)(x-y)-(x+y)^2-2y(x-y)-2xy]/xy 的值为x,y的值无关 解方程 (x+1)^5/(-1-x)^4=3x+7一定要100%正确阿. 化简：3x^2-[5xy-(x^y-3xy)+4x^2y-8xy] 证明 (x+y+z)^2>3(xy+yz+zx)如题,不等式证明, 证明：不存在整数x,y使x²+3xy-2y²=122成立 因式分解 x-xy+3y-3x 2x+xy-y-4x+5y-6 x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2 5x^3y*(-3y)^2+(-6xy)^2*(-xy)+xy^3*(-4x^2) 2x²y-3(2xy-xy)-xy 化简(3x^2-5xy)+{-x^2-[-3xy+2(x^2-xy)+y^2]} 5x^2y/-1/2xy*3xy^2 2xy+5y^2+( )=x^2+3xy 计算：5xy^2-[3xy^2-(4xy^2-2x^2y)]+2x^2y-xy^2 5xy^2-(3xy^2-(4xy^2-2x^2y))+2x^2y-xy^2求 5xy^2-{2x^y-[3xy^2-（xy^2-2x^2y）]/（-1/2xy）} 已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2 2x平方y-2xy+3xy平方+5+2xy+x平方y-3xy平方-3 过程! 5x^2y-3xy^2+4xy-14xy^2+4xy-2x^2y（化简）