2x/x-1 + 1/x+2 =2
[2x(x+2)+(x-1)]/[(x-1)(x+2)]=2
4x²+4x+x-1=2x²+2x-4
2x²+3x+3=0
△=9-24=-15最简公分母是多少？最简公分母是(x-1)(x+2)