2x^2+2xy+y^2=6x-9,则xy的值为

(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)答案应为-2x-x*x-3x， 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) x*x+xy=3,xy+y*y=2,则x*x+2xy+y*y=________? 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=? 函数f(xy,x+y)=x^2+xy+y^2,则df(x,y)=? f(xy,x-y)=x^2+3xy+y^2,则f(x,y)=? 2x^2+2xy+y^2=6x-9,则xy的值为 3x^2-xy /9x^2-6xy+y^2=x/( )=( )/9x^2-y^2 求x^3 - 6x^2y + 11xy^2 - 6y^3 思路x^3 - 6x^2y + 11xy^2 - 6y^3= x^3 - 3x^2y + 2xy^2 - 3x^2y + 9xy^2 - 6y^3= (x^2 - 3xy + 2y^2)(x - 3y)= (x^2 - 2xy - xy + 2y^2)(x - 3y)(x - y)(x - 2y)(x - 3y)求思路 （x^2+xy/x-y)/（xy/x-y)计算 已知x^2-6xy+9y^2=0,求(x-y)/(x+y) x y属于R 2^x=18^y=6^xy则x+y 2x^+xy-y^-4x+5y-6=? 因式分解 x-xy+3y-3x 2x+xy-y-4x+5y-6 -3x^2y+6xy^2-9xy=( )(x-2y+3) 已知x+y=6,xy=-3,则x^2y+xy^2=? 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 xy属于R有2x+y+xy=6,则2x+y最大值?