To set up a linear equation for the scenario described, we can define the variables and the relationship between them.
Let:
- \( t \) be the time in minutes after the water starts draining.
- \( W(t) \) be the amount of water in gallons remaining in the bathtub after \( t \) minutes.
The bathtub starts with 40 gallons of water. Since the water drains at a rate of 8 gallons per minute, the amount of water remaining after \( t \) minutes can be represented by the equation:
\[ W(t) = 40 - 8t \]
Here, \( W(t) \) decreases linearly over time \( t \) due to the steady rate of water draining. This equation shows that initially (when \( t = 0 \)), there are 40 gallons (\( W(0) = 40 \)), and with each passing minute, 8 gallons are subtracted from the total.