x^2-4xy+5y^2+6y+9=0,x+y=

x^2-4xy+5y^2+6y+9=0,x+y= 已知x^2+9y^2-2x-6y+2=0,求{-（xy/（x-y）^2}^4*(y^2-xy/x)^3*x^4/y^10/(x/xy-y^2)^5的值 2x^+xy-y^-4x+5y-6=? 诺x+y=6,xy=4 求(5x-4y-3xy)-(8x-y+2xy) 已知x^2+y^2-4x+6y+13=0求(xy+y^2/5x^2-5xy+xy+y^2)·（5/x+y）-（y/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*y)的值 4xy-[(x²+5xy-y²)-(3xy-1/2y)]x=3,y=-6 因式分解 x-xy+3y-3x 2x+xy-y-4x+5y-6 已知x>0,y>0,x+根号xy-6y=0,求4x+5根号xy-6y分之x+2根号xy 方程组 x^2-xy-2y^2+x+4Y-2=0和2X^2-xy-y^2-x-5y-6=0 已知x^2+5y^2-4xy-6y+9=0求x,y值 已知：x^2+5y^2-4xy-6y+9=0,求x,y的值. 1.已知x+y=-4,xy=3,求5（2分之1xy+2y）+[6x-(2xy+y-3x)]的值2.已知（x+3）^2+|x-y+10|=0求代数式5x^2y-[2x^2y-(3xy-xy^2)-3x^2]-2xy^2-y^2的值 解方程 x^2-4xy+5y^2-6y+9=0 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 若2x^2-6xy+9y^2-4x+4=0,则y/x-x/y=若2x^2-6xy+9y^2-4x+4=0,则y/x-x/y=? 已知x^2-6xy+9y^2=0,求(x-y)/(x+y) 已知x>0,y>0,且x+6y=5根号xy,求(2x+根号xy-y)分之(x+根号xy+2y)的值