已知x+5y=6,求-x^2-5xy-30y的值

已知Y-x=3xy,求(5x+3xy-5y)÷(x-2xy-y) 已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值 已知xy=2(x+y),求5x-xy+5y/3xy-x-y的值 已知x-y=3xy,求5x+2xy-5y/x-4xy-y的值 已知xy/x+y=3,求代数式2x-5xy+2y/x-3xy+y 已知xy/x+y=2,求代数式3x-5xy+3y/-x+2xy-y的值 已知X+Y分之XY=2,求-X+3XY-Y分之3X+5XY+3Y 已知X-XY-2Y=0求2X+3XY-Y/X-2XY+5Y 已知xy/x+y=2,求代数式8x-5xy+8y/-x+3xy-y的值 已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2 已知xy^2=-2,求-xy（x^2y^5-xy^3-y)的值. 已知xy^2=-2 求-xy(x^2y^5-xy^3-y) 已知x-y=6,xy=-2,求3（xy+x-2y）-5(y-2x)+2(xy-x)的值.RT.答对加悬赏. 已知xy^2=-2求xy（2x^3y^7+5x^2y 已知xy^2=-6,求-xy(x^3y^7-3x^2y^5-y）的值 已知xy/x+y=2,求代数式3x-5y+3y/-x+3xy-y 已知xy/(x+y)=2求(3x-5y+3y)/(-x+3xy-y) 已知x,y>0 2x+y+3=xy 求5x+4y最小值