Answer:
(3j) + (3m + 21)
Explanation:
Since every time Jared goes running he runs 3 miles we should multiply j by 3. So we will have: 3j
Since every time Malia goes running she runs 3 miles we should multiply m by 3. So we will have 3m
But this month Jared ran an extra 21 miles so we will have to add that after we have multiplied both j and m by 3.
Since we want the total distance they ran that month, we need to add all of these distances.
This will give us 3j + 3m + 21.
In the answer options 3j is inside a parenthesis as well as 3m + 21. Since inside the parenthesis we only have addition and the order which we add doesn't really make a difference, the parenthesis were unnecessary but they won't affect the answer.