First, we must let:
x = number of tickets intended for adults
y = number of tickets intended for children.
a. Write in terms of x the number of tickets for children
Solution:
x + y = 28 ⇔ y = 28 - x (equation 1)
To answer in terms of x:
no. of tickets for tickets for children = 28 - x
b. the amount spent on tickets for adults
Solution: $30 is the cost of ticket per adult and there are x number of tickets intended for adults.
Therefore,
amount spent on ticket for adults = 30x
c. the amount spent on the tickets.
Solution:
$ 15 = cost of ticket per child
$ 30 = cost of ticket per adult
total amount spent on tickets = 30x + 15y ⇒ (equation2)
substitute equation 1 to equation 2.
(equation 1) y = 28 - x
(equation 2) total amount spent on tickets = 30x + 15y
total amount spent on tickets = 30x + 15(28-x)
total amount spent on tickets = 30x + 420 - 15x
total amount spent on tickets = 15x + 420
