①
(x-4)/(x-5)-(x-5)/(x-6)=(x-7)/(x-8)-(x-8)/(x-9)
②
(x-4)(x-6)-(x-5)(x-5)/(x-5)(x-6)=(x-7)(x-9)-(x-8)(x-8)/(x-8)(x-9)
③
(x*x-10x 24-x*x 10x-25)/(x-5)(x-6)=(x*x-16x 63-x*x 16x-64)/(x-8)(x-9)
④
-1/(x-5)(x-6)=-1/(x-8)(x-9)
⑤
(x-5)(x-6)=(x-8)(x-9)
⑥
x*x-11x 30=x*x-17x 72
x=7
分数线用/代替,不能输你懂得~