So to start off, first combine like terms, so all the a^2 with the a^2’s, the a’s with the a’s, and the normal numbers.
Add the -5a^2, the -a^2, and the -18a^2 together.
-24a^2-12a-6a-4-16+5a
Now add the -12a, the -6a, and the 5a together.
-24a^2-13a-4-16
Lastly add the -4 and -16 together.
-24a^2-13a-20
^^That is your answer^^
Hope this helps!
