Andrew is a submarine commander. he decides to surface his submarine to periscope depth. it takes him 20 minutes to get from a depth of 400 feet to a depth of 50 feet. write an equation in point-slope form that describes this situation. what was the submarine's depth five minutes after it started surfacing?

Since the submarine lost a dept of 350 feet in 20 minutes, we can establish a ratio of (350/20) 17'5 feet lost per minute. This way, we could establish the folloing equation:

y = 400 - 17'5x

where "y" is the depth, and "x" the time passed in minutes since the beginning of the ascension.

The depth five minutes after it started surfacing will be:

y = 400 - 17'5··5 = 312'5 feet