6xy^2-9x^2y-y^3=?(2)(2a-b)^2+8ab=?分解因式

化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) (x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)答案应为-2x-x*x-3x， 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 -3x^2y+6xy^2-9xy=( )(x-2y+3) 3/x —2/y=3 (2x-3y-xy) / (7xy+9y-6x)= 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y x^2-xy-6y^2+3xy+y+2 已知xy/x+y=6,求3x-2xy+3y/-x+3xy-y的值. 已知(xy)/(x+y)=6求(3x-2xy+3y)/(-x+3xy-y)的值. 诺x+y=6,xy=4 求(5x-4y-3xy)-(8x-y+2xy) x^+2xy+y^+4=16 x^-2xy+y^=16 求(3xy+6y^)+|x^-(2xy+2y^-3x^)|的值 2(x*x-3xy-2y*y+2)- =-4y*y-6xy+3x (9x^2y-6xy^2)/3xy ( )*3xy=6x^2y+2xy^2 x*x+xy=3,xy+y*y=2,则x*x+2xy+y*y=________? 化简求值x-4y/2x-7xy+3y×x-2xy-3y/2x+3xy-2y÷3x-6y/4x-4xy+y,其中：x=1999,y=-1 4xy-[(x²+5xy-y²)-(3xy-1/2y)]x=3,y=-6 1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)