已知x/3减y/2+3,求7xy+9y-6x分之2x-3y-xy的值.

已知x=3y,试求（x-y)^2+2xy-y^2/x^2+7xy+y^2 已知x=3y,试求(x-y)^2+2xy-y^2/x^2+7xy+y^2 已知xy^2=-2求xy（2x^3y^7+5x^2y 已知x/3减y/2+3,求7xy+9y-6x分之2x-3y-xy的值. 已知x分之一减y分之一等于3,求x+xy-y分之2x-xy-2y的值 已知X/Y=2/7,求x^2-3XY+2Y^2/X^2-2XY+Y^2 已知x/y=7/2,求2x+3xy+2y/x+2xy+y的值 已知X+Y=3,XY=-1,求2(X-Y)^4-9(X-Y)^2+12XY 已知xy平方=-2,求-xy(x^3y^7-3x^3y^7-y)刚刚发现打错题了，应该是：已知xy平方=-2,求-xy(x^3y^7-3x^2y^5-y) 已知2x+xy=10,3y+2xy=6.求4x+8xy+9y=? 已知x+xy=-3,xy+y=7,试求x+2Xy+y的值 已知xy^2=-2,求-xy(x^3y^7-3x^2y^5-y)的值 已知xy^2=-6,求-xy(x^3y^7-3x^2y^5-y）的值 已知xy^2=-2求xy（2x^3y^7+5x^2y^5-y)的值 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=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=4,xy=2,求代数式2(3x+2xy)+(2xy+3x+2y)-(4xy-7y)的值