Question 661403
fee $30
member $3
non-member $6
x = number of tickets

30 + 3x =  6x
30 + 3x - 3x = 6x - 3x
30 = 3x
30/3 = 3x/3
10 = x

when there are 10 tickets
Proof
30 + 3(10) = 60
6(10) = 60