Subtract a-4 from 4a+16 and simplify your answer. The variable a should appear only once in your answer.

Subtracting from a number means removing from a term.

So we set it up as (4a+16)-(a-4)

Now we distribute the - to a and -4.

So now it is 4a+16-a+4

Combine the like terms to get 4a-a+16+4

So your answer is 3a+20