Answer:

Explanation:
To write this fraction in its simplest form, we simply have to divide any values in the denominator and numerator that can be simplified!
We can see that 9x and 12x can be simplified by dividing them by 3x!
We are now left with:

Now we have to add 3 and 15 to simplify further...
We are left with:

The final step we must take is that we have to change this fraction into a mixed fraction...
Hope this helps, have a lovely day! :)