Answer:
6a + 1
Step-by-step explanation:
First, you need to multiply everything in the brackets by 3L
(7 + 2a) x 3 =
7 * 3 = 21
2a * 3 = 6a
21 + 6a
Now you can subtract the 20 from this:
6a + 21 - 20
Simplified down: