The number of chocolates in a small box is represented by the variable, c. We can write the following expression for 3 small boxes: 3c
Since a large box contains 15 more chocolates than a small box, we can write the following expression for the large box chocolates: c + 15
For the total of 3 small boxes and 1 large, we can add the two expressions:
3 small boxes + 1 large box = 3c + c + 15
Now combine like terms for a final expression of:
4c + 15