A submersible is a type of underwater vessel. Suppose a submersible starts at a depth of 40 feet below sea level, represented by –40 feet. The table shows the submersible's change in depth from one minute to the next.

1. Write and evaluate a subtraction expression to find the depth of the submersible at 2:16 p.m.




2. Write and evaluate a subtraction expression to find the depth of the submersible at 2:17 p.m.




3. Write and evaluate a subtraction expression to find the depth of the submersible at 2:18 p.m.



4. If the submersible dove straight down, what is the distance between the submersible's starting position at 2:15 and its position at 2:18? Show your work.