You have the right idea that things need to get multiplied.
What should be done is that the entire fraction needs to get multipled by the lowest common denominator of both denominators.
Let's look at the complex numerator. Its denominators are 5 and x + 6. Nothing is common with these, so both pieces are needed.
The complex denominator has x - 3 as its denominator. With nothing in common between it and the complex numerator, that piece is needed.
So we multiply the entire complex fraction by (5)(x + 6)(x -3).
Numerator: 
= (x+6)(x-3) - (5)(5)(x-3)
= (x+6)(x-3) - 25(x-3)
= (x-3)(x + 6 - 25) <--- by group factoring the common x - 3
= (x -3)(x - 19)
Denominator:

Now we put the pieces together.
Our fraction simplies to (x - 3) (x - 19) / 125 (x + 6)
Answer: 36
Step-by-step explanation:
1) substitute x for 6
get f(-5)=6(1--5)= 6+30=46
By dividing each general term by 3.
Example:
(3/3=1)
Total friends = 3
fare = $ J
She also paid $5 tip
So there is J amount of money splitted into 3 friends.
That means you divide J/3 .
After Angela also pays additional tip of $5.
That means you also add 5.
So the expression for how much Angela pay in total is: J/3 + 5