Jack bought 7 tickets for a movie. He paid $7 for each adult ticket and $4 for each child ticket. Jack spent $40 for the tickets
Let a = Number of adult tickets and c be the number of child tickets.
7(7 - c) + 4c = 40
49 - 7c + 4c = 40
49 - 3c = 40
Add 3c to each side and subtract 40:
3c = 9
Divide each side by 3:
c = 3
Substitute c = 3 into Equation (2)
a + 3 = 7
Subtract 3 from each side:
a = 4
Let a = Number of adult tickets and c be the number of child tickets.
- 7a + 4c = 40
- a + c = 7
- Rearrange (2): a = 7 - c
7(7 - c) + 4c = 40
49 - 7c + 4c = 40
49 - 3c = 40
Add 3c to each side and subtract 40:
3c = 9
Divide each side by 3:
c = 3
Substitute c = 3 into Equation (2)
a + 3 = 7
Subtract 3 from each side:
a = 4