Answer:
n = 6 is the answer.
Explanation:
As we know the theorem if two cords intersect each other within a circle the product of the measures of the segments of one cord will be equal to the measures of the segments of the other cord.
Hence 7 × (n + 4) = 5 × (n + 8)
7n + 28 = 5n + 40
7n - 5n = 40 - 28
2n = 12
n = 6
Therefore n = 6 is the answer.