To determine the correct expression for the situation described:
- The diver starts at 15 feet below sea level, which is represented as -15 feet.
- The diver swims up 15 feet to reach the surface, which is represented as +15 feet.
Thus, the correct expression to represent the situation is:
\[ (-15) + 15 = 0 \]
This means that starting at -15 feet and swimming up 15 feet brings the diver back to sea level (0 feet).
So the correct response is:
(−15) + 15 = 0