Answer: the price for an adult ticket is $3
Explanation:
Let x represent the price of one adult ticket.
Let y represent the price of one child ticket.
The Martinez family went to play and paid $13 for 1 adult and 4 children. This means that
x + 4y = 13 - - - - - - - - - - -1
The Hernandez family went to the same place and paid $14 for 3 adults and 2 children. This means that
3x + 2y = 14 - - - -- - - - - - - -2
Multiplying equation 1 by 3 and equation 3 by 1, it becomes
3x + 12y = 39
3x + 2y = 14
Subtracting, it becomes
10y = 25
y = 25/10 = 2.5
Substituting y = 2.5 into equation 1, it becomes
x + 4 × 2.5 = 13
x + 10 = 13
x = 13 - 10
x = 3