Question

how do you divide a fraction

Answer 1

5       6

7        8

do the reciprocal of 6/8 OR 5/7.
5        8               40           20/21
                 =              and simplify        
7        6               42            

Answer 2

It's always best to simply multiply by the reciprocal
For example:
$\frac{2}{3} / \frac{3}{4}$ 
The reciprocal basically means to "flip" the fraction so...
3/4 -----> 4/3
(Only flip ONE of the fractions not both of them...you can choose either fraction for flip you'd still get the same answer) 
Now instead of a division problem we have a multiplication problem now our problem looks like this: 
$\frac{2}{3} * \frac{4}{3}$
Now we simply multiply across
$\frac{2*4=8}{3*3=9}$
As you see above I multiplied across to get a final answer of 
$\frac{8}{9}$ 

And that's how you divide a fraction.