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

已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)} 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 （-3x^y+2xy)-( )=4x^+xy [-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y- (2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)+2x^4y^2÷(xy)^2 x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2 已知x-y=4xy，则2x+3xy-2yx-2xy-y xy=-2,x+y=3,求代数式（4xy+12y)+[7x-(3xy+4y-x)] (2x²y-3xy²)-3(x²y-2xy²)+2（x²y-4xy&# 已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值! 3x²y+xy²-[2xy²-4x²y+（x²y-2xy²）