Help me please I’ll give brainlest

Answer:
-17
Step-by-step explanation:
1) rewrite: (3 - n) divided by 2 = 10
2) Multiply both sides: (3-n)/ 2 = 10
3) move constant to the right: 3 - n = 20
4) calculate: -n = 20 - 3 then, -n = 17
5) change signs: n = -17
Hope this helped and wasn’t confusing, good luck! :)