Question

A diver went 25.65 feet below the surface of the ocean, and then 16.5 feet further down, he rose 12.45 feet.

Answer 1

I guess you want to find where the diver ended up.

Taking distance below the surface to be negative we have:-

-25.65 - 16.5 + 12.65

= -42.15 + 12.45

= -29.7 feet

That is 29.7 feet below the surface.

Answer 2

If you are trying to find where he is the answer is -29.7

Hope this helps!