1-1/(x+2)-1/(x+7)=1-1/(x+3)-1/(x+6) 将(x+1)/(x+2)化成[(x+2)-1]/(x+2)=1-1/(x+2)
1/(x+6)-1/(x+7)=1/(x+2)-1/(x-3) 两边同时减去1,且将其中的项移到另一边
1/(x+6)(x+7)=1/(x+2)(x+3) 两边分别通分
(x+2)(x+3)=(x+6)(x+7) 分子相等,分母也相等
x²+5x+6=x²+13x+42
x=-9/2
检验:x=-9/2是方程的解