Answer: There are 7 bricks in the first row of the structure.
Explanation:
Given function:
which represents the number of bricks in row r of a structure.
If we put r=1, we get the number of bricks in first row.

Therefore, There are 7 bricks in the first row of the structure.
Thus, the value of 7 represents that there are 7 bricks in the first row of the structure.