Question

Adding rational numbers:

after swimming 60 feet below the surface of the water, a whale swims up 30 feet. use a number line to help you create an equation that shows the new location of the whale in relation to the water's surface.

ANSWER:

A. The equation is -60 + 30 = 30. The whale is 30 feet below the waters surface.

B. The equation is -60 + (-30) = -90. The whale is 90 feet below the waters surface.

C. The equation is -60 + 30 = -90. The whale is 90 feet below the waters surface

D. The equation is -60 + (-30) = -30. The whale is 30 feet below the waters surface.​

Answer 1

I belive the answer is A.

Explanation:

Answer 2

First, in standard notation, we must define our zero.

In this case, would make sense to define the zero in the surface of the water.

(below is a number line so you can see the process to think this)

Then if the whale is swimming 60ft bellow the surface of the water, then the first position of the whale is:

-60

Now the whale goes up 30ft, then the new position of the whale is:

-60ft + 30ft = -30ft.

The correct option is A:

The equation is -60 + 30 = -30. The whale is 30 feet below the water's surface.

(you wrote that the equation was equal to +30 instead of -30 in the option A, i supposed that it was a typo)