Question

20=8+v i dont know how to do this

Answer 1

You subtract 8 from both sides so the answer is v=12

Answer 2

20 = 8 + v equals v = 12.

First,  subtract 8 from both sides. Your problem should look like: 20 - 8 = v
Second,  simplify 20 - 8 to get 12. Your problem should look like: 12 = v.
Third, switch sides to get v = 12, which is the correct answer.