You buy 12 tickets and the total is $120. a student ticket is $9 and an adult ticket is $12. how many student tickets did you buy

4 adult tickets were sold and 8 student tickets were sold.

How did I get this?

First, let's see what information is given:

12 tickets sold

(S) tudent ticket = $9

(A) dult ticket = $12

Total cost = $120

So, we know student tickets plus adult tickets total up to $12. We can create an equation out of this: S + A = 12

And we know $9S + $12A = $120

The variables represent the amount of tickets sold, which is unknown.

A = 12 - S, substitute this into the second equation.

9s + 12 (12-s) = 120

Distribute the 12 into the parenthesis.

9s + 144 - 12s = 120

Combine like terms

-3s + 144 = 120

Subtract both sides by 144, left side cancels out.

-3s = - 24

s = - 24/-3

s = 8

So, 8 student tickets were sold. Plug the value of s into our first equation.

A = 12 - 8

A = 4 (adult tickets)