a) Write an expression to describe the journey of the yellow submarine.
-> ((0 - 40) + 30) - 25
[] Sea level = 0
[] The descend 40 meters = -40
[] After examining the sea, they rose 30 meters = + 30
[] They dove 25 meters to look at an octopus = -25
b) At what depth did they stop to look at the octopus?
-> -35 meters
[] The started at 0 (0), descended 40 (-40), rose 30 (-10), and then sove 25 (-35) to see the octopus
[] Another way to think of this is to simplify our previous expression completely
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I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather