Answer:
Equation: 
Solution: 
Step-by-step explanation:
Let be "t" the number of movie tickets bought by the group of friends.
According to the information given in the exercise, the price of each movie ticket is: $8.50.
Then, you can represent the amount (in dollars) the group of friends spent in movie tickets, with this expression:

You know that one person spent $6.50, then the expression that represents the total amount (in dollars) the group of friends spent in food and movie tickets, is:

Since that total amount spent is given in the exercise, you can write the following equation to determine how many tickets were bought:

Finally, you can solve for "t" in order to find the solution of the equation. This is:
