(-1/5xy)*(5/3x^2 y-10/3x^3y^2+1)

5x^2y/-1/2xy*3xy^2 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= 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 计算：(5-xy/x^3-x^2y)/(1-5/xy)^2*(y-x)^3 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 xy^2-5x^2y+1/2xy^2+2/3x^y 5xy平方+3x平方y-xy平方-2x平方y-1 合并同类项 (5x²y-2xy²-3xy)-(2xy+5x²y-2xy²),x=-1/5,y=-1/3 先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y),其中x=-1/2,y=-5 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 【数学】已知 1/x-1/y=3 求 5x-xy-5y / x-2xy-y=?已知 1/x=1/y 求 2x-3xy-2y / x-2xy-y=? 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, 已知1/x-1/y=5,求分式2x+5xy-2y/3x-xy-3y 已知1/x-1/y=3,求5x+3xy-5y/x-2xy-y的值 已知1/x-1/y=3,求x-2xy-y/5x+3xy-5y的值