如果x-y＝2,xy=3,则x²y-xy²=几

如果x：y=2:3,求x²+xy+2y²/x²-xy+y² 已知X/Y=2,则X²+2XY-3Y²/X²-XY+Y²=? 已知x:y=3:2,求(x²+3xy)/(xy+2xy) X²+2xy+y²/xy乘x²-2xy+y²/xy+y²= 已知x-y=4xy，则2x+3xy-2yx-2xy-y 已知x/y=3,求(x²+2xy-3xy²)/(x²-xy+y²) 已知：X+Y=-3,XY=2,X²Y+XY² 已知x²-3xy+4x=3,y²+xy-4y+7=0,则xy-1/2(x²+y² 化简求值3x²y-[2xy-2（xy-3/2x²y)+xy]+3xy²其中x=3、y=-1 如果x^2+xy+y-14,y^@+xy+x=28,求x+y的值. 一.x-y=2,则x²-2xy+y²= 二.x-y=-1,xy=3,则x³y-2x 3xy²-[xy-2(xy-3/2x²y)+3xy²]+3xy²,其中x=3,y