Asubmarine is 1,275.5 feet below sea level. it dives down 215.5 feet and then rises 125.5 feet. finally, the sub dives down another 122.4 feet. assume sea level is at an elevation of 0 feet.
after its final dive, the submarine is at an elevation
feet.

The elevation of submarine is −1487.5 feet that means the submarine is 1487.5 feet below the sea level.

Step-by-step explanation:

We are given the following information in the question:

A submarine is 1,275.5 feet below sea level.

It dives down 215.5 feet

It rises 125.5 feet.

Finally, the sub dives down another 122.4 feet.

We are given that the sea level is at an elevation of 0 feet.

Elevation of submarine is given by:

The elevation of submarine is −1487.5 feet that means the submarine is 1487.5 feet below the sea level.

the solution is h=10 because you add 9 to each side of the equation.