Answer: y = -9x − 10
Step-by-step explanation: y represents the elevation of the bottlenose dolphin. The dolphin begins at 10 feet below sea level or -10. It then becomes to dive, go deeper under the water at a rate of 9 feet per second, or -9.
The equation y = -9x - 10 will equal the amount of feet below sea level that the dolphin is at. Below sea level will always be indicated with a negative number.