Question 44998
{{{13/(f-8)  + 1/(8-f)}}}
Multiply everything by the denominators.
First, multiply by (f-8):
{{{13  + (f-8)/(8-f)}}}
Now multiply by (8-f):
{{{13(8-f)  + (f-8)}}}
Expand the brackets:
{{{104-13f+f-8}}}
{{{96-12f}}}
That is the most simple form to write the fraction you started with.
I hope this helps.
P.S. I am trying to start up my own homework help website. I would be extremely grateful if you would e-mail me some feedback on the help you received to adam.chapman@student.manchester.ac.uk
Adam