Answer:
Explanation:
From the problem statement, we can set up the following equation:
![3N + S = 79](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mvzp19hliovidrtwmxqqb0akf6pk19h46i.png)
where
is the number of tickets each friend got, and
is the number of tickets that Shaunee got. We know that Shaunee got 25, so we know
and can plug that into the equation:
![3N + 25 = 79](https://img.qammunity.org/2020/formulas/mathematics/middle-school/teep1kbqx0cmpfhw9kqv8cwdlnwhsclrkv.png)
Subtracting 25 from each side gives us the following:
![3N = 54](https://img.qammunity.org/2020/formulas/mathematics/middle-school/7bc1k62qive0es54rge1z3ef3bb7vbe0sn.png)
Dividing both sides by 3 gives us the answer:
![N = 18](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mcdwgje6hwo1v67zawm3bdkgmbalnnkaby.png)