已知X-XY-2Y=0求2X+3XY-Y/X-2XY+5Y

问题描述:

已知X-XY-2Y=0求2X+3XY-Y/X-2XY+5Y

X-XY-2Y=0 (X-2Y)(X+Y)=0 X=2Y 或 X=-Y 当X=2Y时 2X+3XY-Y/X-2XY+5Y=13/5 当X=-Y时 2X+3XY-Y/X-2XY+5Y=-2/8=-1/4