PLEASE HELP THANKS!!

Answer: a) x = 5 b) x = 12
Step-by-step explanation: For each one you just do the inverse to get it on the other side of the equal sign. For example x + 3 = 8 would be like this :
1. x + 3 = 8
2. x + 3 - 3 = 8 -3
( + 3 - 3 cancels out)
3. x = 5