Explanation:
If Marisol walks +5 feet East, but Ruperta walked -5 feet East (+5 feet West), the total distance apart is 10 feet.
30 ft below sea level is represented as -30.
Absolute value is a number's distance from 0, no number can be a negative distance from 0.
-30 is 30 away from 0, therefore the Absolute value is 30.