1-1/(x-5)-1+1/(x-6)=1-1/(x-8)-1+1/(x-9)1/(x-6)-1/(x-5)=1/(x-9)-1/(x-8) 1/(x-6)+1/(x-8)=1/(x-5)+1/(x-9) (2x-14)/(x-6)(x-8)=(2x-14)/(x-5)(x-9)2x-14=0时,等式恒成立,此时x=72x...你看了题目么。。看了，怎么没看，
（x-6）/（x-5）=1-1/(x-5)
下面的同理！