已知A+2（x-xy+y)=2x+3y,则A=————————

已知：A=X*X-3xy+y*y,B=2x*x+xy-3y*3y.求A+B,A-B,A+2B 已知a=x^+xy+y^ b=-3xy-x^求2A-3B 已知A+2(x-xy+y)=2x+3y,则A=? 已知x+y=a,x-y=b.求:x^2+y^2;xy 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xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y 已知x+xy+y=3,则(3x+2xy+3y)/(2x+xy+2y)= 已知:x/y=-2,求x^2-2xy-3y^2/x^-6xy 已知x-y=3xy,则2x+3xy-2y除以x-2xy-y=? 已知x-y=3xy,则2x+3xy-2y/x-2xy-y= 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 已知x-y=3xy,求2x-3xy-2y/x-2xy-y 已知y=3xy+x,求代数式2x+3xy-2y/x-2xy-y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