Answer:
The money each boy had after buying his ticket is <u>$2.50</u>.
Step-by-step explanation:
Given:
Miguel and three of his friends went to the movies. They originally had a total of $40. Each boy had the same amount of money and spent $7.50 on a ticket.
Now, to find the money each boy had after buying his ticket.
Let the money each boy had after buying his ticket be 
Total number of boys = 4.
Total money they had = $40.
Money each boy spent = $7.50.
Now, to write an equation:

Now, to solve the equation for getting the money each boy had after buying his ticket:


<em>Subtracting both sides by 30 we get:</em>

<em>Dividing both sides by 4 we get:</em>

Therefore, the money each boy had after buying his ticket is $2.50.