Answer:
a + c = 150
7.75a + 10.25b = 1470
Explanation:
Let a represent the number of adult tickets that were sold.
Let c represent the number of child tickets that were sold.
The celluloid cinema sold 150 tickets to a movie. Some of these were child tickets and the rest were adult tickets. This means that
a + c = 150 - - - - - - - - - - - - - -1
A child ticket cost $7.75 and an adult ticket cost $10.25. If the cinema sold $1470 worth of tickets, it means that
7.75a + 10.25b = 1470 - - - - - - - - -2