Tickets to a show cost $10.50 for adults and $8.50 for students. A group of friends purchased 15 tickets for $149.50. How many adult tickets were purchased?

x - number of adult tickets

y - number of student tickets

{10.5x + 8.5y = 149.5

{x + y = 15

{x = 15 - y

{10.5(15 - y) + 8.5y = 149.5

{x = 15 - y

{157.5 - 10.5y + 8.5y = 149.5

{x = 15 - y

{-2y = -8

{y = 4

{x = 11

They purchased 11 adult tickets.

11 adult tickets were purchased.

Step-by-step explanation:

Let x represent the number of adult tickets that were purchased.

Let y represent the number of adult tickets that were purchased.

A group of friends purchased 15 tickets. This is expressed as

x + y = 15

Tickets to a show cost $10.50 for adults and $8.50 for students. The total cost of the tickets purchased is

$149.50. This is expressed as

10.5x + 8.5y = 149.5 - - - - - - - - - - - -1

Substituting x = 15 - y into equation 1, it becomes

10.5(15 - y) + 8.5y = 149.5

157.5 - 10.5y + 8.5y = 149.5

- 10.5y + 8.5y = 149.5 - 157.5

- 2y = - 8

y = - 8/ - 2

y = 4

x = 15 - y = 15 - 4

x = 11

the answer for this question is 38

the battle of gettysburg is considered the "high water mark" of the confederacy because it marked the greatest advance of the confederate forces against the union.