x^2-2xy-3y^2+4x+8y-5因式分解

化简：3x^2-[5xy-(x^y-3xy)+4x^2y-8xy] 因式分解 x-xy+3y-3x 2x+xy-y-4x+5y-6 诺x+y=6,xy=4 求(5x-4y-3xy)-(8x-y+2xy) 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) 因式分解:12xy^2(y-x)+xy^3(x-y)+4x^2y(x-y) 计算：（1）8x^2y^2*(-3x/4y^5) (2)(x+y)^2/xy-y^2*(y-x)^2/xy+y^2 3(x-y)²-7(x-y)+8(x-y)²+6(x-y)求详细过程（2） 5xy-4x²y-8xy²+3xy-xy²+4x²y x²-y²+5x+3y+4（x+y-2xy)(x+y-z)+(xy-1）² （5x-4y-3xy）+（8x+y-2xy)合并同类项 x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2 5x^3y*(-3y)^2+(-6xy)^2*(-xy)+xy^3*(-4x^2) 已知xy/x+y=2,求代数式8x-5xy+8y/-x+3xy-y的值 已知x-y=3xy,求5x+2xy-5y/x-4xy-y的值 x+y=8,xy=-2,求(5xy+4x+7y)+(6x-3xy)-(4xy-3y)的值 (-2xy+2x+5y)-(3xy+2y-2x)-(x+4y+xy)其中x-y=4xy=-1 若x-y=4,xy=1,则(2x+y-2xy)-(3x+2y+xy)-(4xy+3y-5x)= 求（3x^+y^-5xy）-【2x^-（-4xy-y^+7x^）】=? 求（3x^+y^-5xy）-【2x^-（-4xy-y^+7x^）】=?