s=cost per student ticket
a=cost per adult ticket
value=(students vlue)+(adults value)
student value=(cost per student) times number of students
adult value=(cost per adult) times number of adults
you sell 8 adult and 6 students and that is a value of 126
8a+6s=126
friend sell12 adult and 13 student and get 209
12a+13s=209
so we have
8a+6s=126 and
12a+13s=209
it might help to simplify the first equaiton by dividing by 2
4a+3s=63
we have
4a+3s=63
12a+13s=209
multiply first equaton by -3
-12a-9s=-189
add to secont equaiton
12a+13s=209
-12a-9s=-189 +
0a+4s=20
4s=20
divide 4
s=5
each student ticket costs $5.00
