Answer:
$129
Explanation:
Let us represent:
Cost Adult tickets = x
Cost Children's tickets = y
The total cost of ticket = C =
A family goes to an amusement park adult tickets cost $21 children under 10 years of age pay $15
C = $21 × x + $15 × y
C = 21x + 15y
The total cost of 4 adult tickets and 3 children's tickets is calculated as:
C = 21 × 4 + 15 × 3
C = 84 + 45
C = $129