Question

已知xy≠0，且2x+3xy-2y=0,求(x+y)/(x-y)的值。求大神帮助

换元法解答，要详细过程~

Answer 1

2X^2+3xy-2y^2=0 (2x-y)(x+2y)=0 即：2x-y=0或，x+2y=0 y=2x或x=-2y 当y=2x时：x+y/x-y=3x/(-x)=-3 当x=-2y时：x+y/x-y=-y/(-3y)=1/3