7. Mr. Newman bought 8 tickets to a chili supper and spent a total of $30. He bought a combination of adult tickets for $5 each and child tickets $3 each. Which system of equations below will determine the number of child tickets, c, and the number of adult tickets, a, he bought?

Respuesta :

So, there are two equations.

5a + 3c = 30

a + c = 8, therefore, a = 8 - c


5a + 3c = 30

5(8 - c) + 3c = 30

40 - 5c + 3c = 30

-2c = -10

c = 5 , So a = 3

The answer is D. 5a + 3c = 30 a + c = 8