Respuesta :

Greetings!

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:

6a + 1


Hope this helps!