若xy

若xy+z 若xy＝2 若不等式根号(3xy) 若(1)xy>0,(2)xy<0,求|x|/x+|y|+|xy|/xy的值 若x＞1，y＞0且满足xy=xy，xy＝x 若xy³=-3,则-xy【x²y五次方-xy³-y】的值为 若多项式x^2+(2m-6)xy+y^2+9+2xy合并后不含xy项,求m值 若x-y=5,xy=6,求x^2-xy^2和x^2y+xy^2 1若x+2y=0 ,xy不等于0,求分式 x^2+2xy / xy+y^2 若x+2y=0,xy不等于0,求分式x²+2xy/xy+y²的值 若(y-x)/xy=3,求分式(2x+3xy-2y)/(x-2xy-y)的值 若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少?