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## Algebra (all content)

### Course: Algebra (all content)>Unit 7

Lesson 18: Modeling situations by combining and composing functions (Algebra 2 level)

# Model with function combination

## Problem

A partially filled pool has 10, comma, 000 liters of water in it when Finn begins to fill it with a hose on a hot, sunny day. The volume, V, in liters, of water coming out of the hose in m minutes is given by the function V, left parenthesis, m, right parenthesis, equals, 20, m, and the volume, E, in liters, of water evaporating in m minutes is given by the function E, left parenthesis, m, right parenthesis, equals, 0, point, 1, m.
Let P be the total volume, in liters, of the water in the pool m minutes since Finn started filling it.
Write a formula for P, left parenthesis, m, right parenthesis in terms of V, left parenthesis, m, right parenthesis and E, left parenthesis, m, right parenthesis.
P, left parenthesis, m, right parenthesis, equals
Write a formula for P, left parenthesis, m, right parenthesis in terms of m.
P, left parenthesis, m, right parenthesis, equals
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