Question

Let’s write an expression to represent the number of liters left in Tank A after t minutes, where t represents the number of minutes. We’ll go step by step. How much water starts in Tank A?
Tank A
starts with 400 liters
leaking 3 liters per minute


?
+ ?
Tank B
starts with 180 liters
filling 5 liters per minute

Answer 1

To represent the number of liters left in Tank A after \( t \) minutes, we start with the initial amount of water in the tank and then account for the rate at which it is leaking.

1. **Initial amount of water in Tank A:** 400 liters.
2. **Rate of leakage from Tank A:** 3 liters per minute.

The expression to calculate the amount of water left in Tank A after \( t \) minutes subtracts the total amount leaked over that time from the initial amount.

The amount leaked after \( t \) minutes is given by:
\[
\text{Amount leaked} = \text{leak rate} \times t = 3 \, \text{liters/minute} \times t
\]

Thus, the amount of water left in Tank A after \( t \) minutes can be expressed as:
\[
\text{Liters left in Tank A} = \text{Initial amount} - \text{Amount leaked}
\]
\[
\text{Liters left in Tank A} = 400 - (3t)
\]

Therefore, the expression for the number of liters left in Tank A after \( t \) minutes is:
\[
400 - 3t
\]