(-3/4x^2y-3/5xy^2+1)(-2/3xy)^2

若x-y=4,xy=1,则(2x+y-2xy)-(3x+2y+xy)-(4xy+3y-5x)= (-2xy+2x+5y)-(3xy+2y-2x)-(x+4y+xy)其中x-y=4xy=-1 化简：3x^2-[5xy-(x^y-3xy)+4x^2y-8xy] 4xy-[(x²+5xy-y²)-(3xy-1/2y)]x=3,y=-6 x²-y²+5x+3y+4（x+y-2xy)(x+y-z)+(xy-1）² 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) XY(XY+3)+(XY+4)+4(X+Y+1)-(X+Y+2) 5xy平方-2x平方y+[3xy平方-(4xy-2x平方y-2x平方y)],其中x=-2,y=-1求值 5x^2y/-1/2xy*3xy^2 已知1/x+1/y=5,求x+y+3xy/2x-4xy+2y的值,已知1/x+1/y=5,x+y+3xy/2x-4xy+2y的值, 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 5x^2y-3xy^2+4xy-14xy^2+4xy-2x^2y（化简） 5xy^2-{2x^y-[3xy^2-（xy^2-2x^2y）]/（-1/2xy）} 已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y= 已知2/x-1/y=3,则(2y-x+4xy)/(3x-6y-5xy)=?