Question

find x if f(x) = 3.

1. the water level (in feet) of a pool d days without rain is represented by the function: w(d)=9 - 0.1d

find and explain w(4).

Explanation:

Step1: Substitute d = 4 into the function

Substitute \(d = 4\) into \(w(d)=9 - 0.1d\). So we get \(w(4)=9-0.1\times4\).

Step2: Perform the multiplication

First, calculate \(0.1\times4 = 0.4\). Then the expression becomes \(w(4)=9 - 0.4\).

Step3: Perform the subtraction

\(9-0.4 = 8.6\).

The value of \(w(4)\) represents the water - level of the pool (in feet) 4 days without rain. Since the function \(w(d)\) gives the water - level after \(d\) days without rain, when \(d = 4\), the water - level of the pool is 8.6 feet.

Answer:

\(w(4)=8.6\). It means the water level of the pool is 8.6 feet 4 days without rain.