Final answer:
Jack bought 4 adult tickets and 3 child tickets for a total of 7 tickets.
Step-by-step explanation:
If Jack bought 7 tickets to a movie and paid $7 for each adult ticket and $4 for each child ticket, and he spent $40 for the tickets, we can set up an equation to solve for the number of tickets Jack bought.
Let x be the number of adult tickets and y be the number of child tickets. We can write the equation:
x + y = 7
and
7x + 4y = 40
To solve the system of equations, we can multiply the first equation by 4 and subtract it from the second equation:
7x + 4y - 4x - 4y = 40 - 4 * 7
3x = 12
x = 4
Substituting x = 4 into the first equation, we get:
4 + y = 7
y = 3
Therefore, Jack bought 4 adult tickets and 3 child tickets for a total of 7 tickets.