当实数x,y满足xy+x+y+7=0,3x+3y=9+2xy,则x平方y+xy平方=多少

当实数x,y满足xy+x+y+7=0,3x+3y=9+2xy,则x平方y+xy平方=多少 已知实数x、y满足2x2-7xy+3y2=0,求x：y 已知正实数x y满足x-根号xy-2y=0求 x+3根号xy+2y/2x-2根号下xy-y 若两个正实数x,y满足x^2+2xy-3y^2=0,求x^2+xy+y^2/x^2-xy+y^2 实数x,y满足x^3-y^3-3xy=1,则x-y= 若实数x,y满足x^2-xy-y^2 =0,则x/y=? 已知实数x,y满足|x+y+7|+(xy-5)^2=0,求3x^2y^3+3x^3y^2 数学竞赛题：若实数x,y满足方程组xy+x+y+7=0,3x+3y=9+2xy,则x2y+xy2=? 已知实数x、y满足xy>0,且8/xy+1/x+1/y=1, 设正实数x,y,z满足x*x-3xy+4y*y-z=0,则当xy/z取得最大值时,2/x+1/y-2/z的最大值为? 当实数x,y,满足约束条件{x>0 y>=x 2x+y+k 当x,y为实数,满足x²+3y²-12y+12=0求y^x 已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y 若正实数xy满足x+y+3=xy.求xy的最小值 已知实数xy满足x^2+3x+y-3=0 则x+y的最大值为 若实数x,y满足根号x-2 +(3-y)^2=0,则代数式xy-x的值为 若实数xy满足x-y+1 已知实数xy满足x+2y