若9x^2+y^2+24x-6y+25=0,则xy=

2 21.（2x+3y) -（x+2y) 2 2 2 22.3|x-3|+x -6xy+9y =0 则x y+2xy=? 化简求值,若X方-2XY+Y方+1XY-11=0,求X方+6XY+9Y方分之X方-25Y方*5X-25Y分之X+3Y的值 7.X*X+2X+Y*Y-6Y+10=0,则xy=? 若4x²+4xy+2y²+6y+9=0,则x-y=_____ 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y* 若x+y-5xy=0,求(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? 若实数xy满足x^2+y^2-2x+6y=0 则x-2y的最大值 已知x-y=3xy,且xy不等于0,则-3x+6xy+3y/(7x-5y)-9xy-(3x-y) {x,xy,lg(xy)}={0,|x|,y} 则log8（X^2+Y^2） 已知x^2+y^2-6x-8y+25=0,则xy= 已知x.x+y.y+8x+6y+25=0,求代数式(x.x-4y.y)/(x.x+4xy+4y.y)-x/(x+2y)的