Question

A scientist was in a submarine below sea level, studying ocean life. Over the next ten minutes, she rose 22.3 feet. How many feet had she been below sea level, if she was 39.6 feet below sea level after she rose?

Answer 1

To find out how many feet below sea level the scientist was initially, we can set up the situation as follows:

Let \( x \) be the depth (in feet) below sea level before she began to rise. After rising 22.3 feet, she is then at a depth of 39.6 feet below sea level.

We can express this relationship mathematically:

\[
x - 22.3 = -39.6
\]

Here, we subtract 22.3 from her initial depth \( x \) because she is rising, and the result equals -39.6 (which indicates how many feet she is below sea level after the rise).

Now, let's solve for \( x \):

\[
x - 22.3 = -39.6
\]

Adding 22.3 to both sides:

\[
x = -39.6 + 22.3
\]

Calculating the right side:

\[
x = -39.6 + 22.3 = -17.3
\]

So, the scientist was **17.3 feet below sea level** before she rose.