To solve this problem, we must remember that the distributive property allows us to get rid of parentheses by multiplying the coefficient by each of the terms in parentheses. In this case, our coefficient is 3, because that is the number of dollars Ann and Joe's father will donate per lap. This means that we must multiply this by the total number of laps that they swam, which can be found by adding together their individual number of laps, 21 + 15.
This makes our expression: 3(21 + 15)
Using the distributive property, we can multiply both numbers in the parentheses by 3 to simplify our expression, as shown below:
3(21) + 3(15)
Now, we must multiply these numbers together to simplify.
63 + 45
When we add these two numbers together, we get 108.
Therefore, your final answer is that their father donated $108.
Hope this helps!
