化简：(x^4+x^3y-xy^3-y^4)/(x^4-x^3y+x^2y^2+xy^3-2y^4)

化简：3x^2-[5xy-(x^y-3xy)+4x^2y-8xy] 化简2(x²y+xy)-3(x²y-xy)-4x²y 化简3（x²y+xy)-4(x²y-xy)-5x²y, 因式分解:12xy^2(y-x)+xy^3(x-y)+4x^2y(x-y) -x-3xy+y 化简：2x²y+{2xy-[3x²y-2(-3x²y+2xy)]-4xy}化简：2x²y+{2xy-[3x²y-2(-3x²y+2xy)]-4xy} 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) 因式分解 x-xy+3y-3x 2x+xy-y-4x+5y-6 【x(xy-xy)-y(x-xy)】÷3xy 化简：(x^4+x^3y-xy^3-y^4)/(x^4-x^3y+x^2y^2+xy^3-2y^4) 5x^2y-3xy^2+4xy-14xy^2+4xy-2x^2y（化简） 已知x+y=4,x-y=6,化简xy（y²+y）-y²（xy+2x）-3xy 化简:-3{y-(3x^2-3xy)}-{y+2(4x^2-4xy)}版本 化简4xy-3y²-3x²+xy-3xy-2x²+x²-2y² （-3x^y+2xy)-( )=4x^+xy 分解因式 x(x-y)^5+xy(y-x)^4-x^3(x-y)3 x/3=y/4,求(x*x-xy)/(x*x+y*y)的值 x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x²