化简xy/[(100-x)*8]=3/20

化简:xy分之3x^2+2xy-xy分之2x^2-xy= 化简：3x^2-[5xy-(x^y-3xy)+4x^2y-8xy] (8xy-3x平方)-5xy-2(3xy-2x平方),其中,x=2,y=-1 已知xy/x+y=2,求代数式8x-5xy+8y/-x+3xy-y的值 诺x+y=6,xy=4 求(5x-4y-3xy)-(8x-y+2xy) 化简xy/[(100-x)*8]=3/20 2x平方-3xy+(2xy-x平方)化简! 因式分解x^3+2xy-x-xy^2= （-3x^y+2xy)-( )=4x^+xy 化简(3x^2-5xy)+{-x^2-[-3xy+2(x^2-xy)+y^2]} x+y=8,xy=-2,求(5xy+4x+7y)+(6x-3xy)-(4xy-3y)的值 [(2xy^3)^2÷(3x)]·[8xy÷(4xy)],其中x=1000,y=-1 已知2x+xy=10,3y+2xy=6.求4x+8xy+9y=? 已知x^+xy=-5,xy+y^=8,求2x^-xy-3y^的值都是2次 化简（3X平方-5Xy)+{-X平方-[-3Xy+2(X平方-xy) [(2xy的立方)整体的平方/(3x)]*[8xy/4xy]其中x=1000,y=-1 (x^3+3x^2-2xy^2+1)+(-xy^2+x^2-2X^3+2)+(x^3-4x^2*y+3xy^2-8)= XY/(100-X)=3/20 , 2XY/(100-2X=2/5 怎么解?