Solution:
The fish is swimming 5 feet under the water surface will be represented below as
5 feet take negative because the fish is swimming below the surface of the water.
The fish then descends 10 feet down,This can be represented below also
10 feet take negative because the fish descends
The fish then ascends (goes up) by 4 feet
This can be represented below as
Concept:
To calculate the depth of the fish means to add up all the depth
By applying the concept, we will have
Hence,
The fish is 11 feet under the water surface