Aswimmer dives 10 feet below the surface of a lake
how far must she swim before she reaches the surface?
use an addition equation to explain, and tell what each
part of the equation means.

She must swim 10 feet before she reaches the surface; from level -10 to level 0 (Equation: )

Step-by-step explanation:

Based on the information provided, you can assume that the surface of the lake is at level 0.

 You know that the swimmer dives 10 feet below the surface; this is the level -10 .

This means that she must swim 10 feet from the level -10  to the level 0 in order to reach the surface of the lake.

Therefore, to find how far she must swim before she reaches the surface, it is necessary to add levels -10 and +10 to get the level 0. This can be represented with the following equation: