Question

A swimmer dives 10 feet below the surface of a lakeHow far must she swim before she reaches the surface?Use an addition equation to explain, and tell what eachpart of the equation means.​

Answer 1

The swimmer must swim 10 feet before she reaches the surface; from level -10 to level 0 (The equation is:
`-10+10=0`)

Explanation:

We can assume that the surface of the lake is at level 0.

The swimmer dives 10 feet below the surface; then this is the level -10.

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

Therefore, in order to calculate 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:

`-10+10=0`