Simplify the expression by combining like terms from highest to lowest power of the variable -5a^2 -12a-6a-4-a^2-16-18a^2+5a

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!