help on number 12 please

Answer:
Step-by-step explanation:
a=adult ticket
s=student ticket
5a+18s=114
4a+6s=66
multiply by 3
12a+18s=198
12a+18s-5a-18s=198-114
7a=84
a=12
4×12+6s=66
6s=66-48
6s=18
s=3
cost of adult ticket=12 $
cost of student ticket=3 $