已知3x+2y=6,xy=3,求2/x+3/y的值

已知:x/y=-2,求x^2-2xy-3y^2/x^-6xy 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. 已知x/y=2,求 [x^2-xy+3xy^2 ] / [ x^2+xy+6y^2]的值 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y 已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理.已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理. 已知x/y=2,求(x^2-xy+3y^2)/(x^2+xy+6y^2)的值 已知x+y=-2,求代数式(6xy+10y)+[4x-2(3xy+2y-x)] 已知x/y=2,求x²-xy+3y²/x²+xy+6y²的值 已知x/y=2,求x²-xy+3y²/x²+xy+6y²的值 已知x-y=6,xy=-1,求(2x+3x-2xy)-(x+4y+xy)-(3yx-2x+2y)的值 已知xy/x+y=3,求2x-3xy+2y/-x+3xy-y的值 已知xy/x+y=3,求2x-3xy+2y/-x+3xy-y的值 已知x-y=3xy,求分式3x+2xy-3y/x-2xy-y的值 已知y=3xy+x,求代数式2x+3xy-2y/x-2xy-y的值 已知x-y/xy=3,求分式2x+3xy-2y/x-2xy-y的值. 已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y) 已知x-y=3xy,求2x+3xy-2y/x-2xy-y