Respuesta :

Descending: subtraction

Rises: Addition

The diver descends 100ft: Position -100 (the 0 is the sea level)

Then rises 28: Add 28 to the previous position: Position -72

[tex]-100+28=-72[/tex]

...before descending another 33: Subtract 33 to the previous position:

[tex]-72-33=-105[/tex]

Then, the final position is -105ft (105 ft under the sea level)