1/(x+4) - 1/(x+1) =1/(x+3)-1/x
问题描述：
1/(x+4) - 1/(x+1) =1/(x+3)-1/x
答
（x+1-x-4）/[（x+4）（x+1）]=(x-x-3)/[x(x+3)]
-3/[(x+4)(x+1)]=-3/[x(x+3)]
x^2+5x+4=x^2+3x
x=-2
检验：把x=-2代入x+4不等于0,x+1不等于0,x+3不等于0,x不等于0.所以x=-2是原分式方程的解