解方程(X+1 )/(X-2)+(X+2)/(X-1)=2

（x+1）/(x-2)+(x+2)/(x-1)=2
[(x+1)(x-1)]/[(x-2)(x+1)]+[(x+2)(x-2)]/[(x-1)(x-2)]=2
(x*x-1)/(x*x-3*x+2)+(x*x-4)/(x*x-3*x+2)=2
(2*x*x-5)/(x*x-3*x+2)=2
2*x*x-5=2*x*x-6*x+4
6*x=9
x=3/2

（2)答案是1/x(x+1)
1/x(x+1)
=x+1 / x(x+1) - x/x(x+1)
=1/x(x+1)

是前者。可我化简时没有这么一步。
通分（x²-1+x²-4）/(x-1)(x-2)=2
2x²-5=2x²-6x+4
x=3/2