The Smiths are draining their 25,000 gallon swimming pool. It drains at a rate of 3,000 gallons an hour. Write a function that models the amount of water in the pool after t hours.

you need a linear function.

It starts at (0,25000) and has a slope of -3000

F(t) = -3000t + 25,000.

To write a function that models the amount of water in the pool after t hours, we can start by defining the initial amount of water in the pool, which is 25,000 gallons. Since the pool drains at a rate of 3,000 gallons per hour, the amount of water in the pool after t hours can be calculated by subtracting the amount drained in t hours from the initial amount.

The function can be defined as follows:
```python
def calculate_water_in_pool(t):
initial_water = 25000
drain_rate = 3000
drained_water = drain_rate * t
water_in_pool = initial_water - drained_water
return water_in_pool
```

In this function, we first define the initial_water variable to store the initial amount of water in the pool (25,000 gallons) and the drain_rate variable to store the rate at which the pool drains (3,000 gallons per hour). Then, we calculate the drained_water variable using the formula `drain_rate * t`, where t is the number of hours passed. Finally, we calculate the water_in_pool by subtracting the drained_water from the initial_water and return this value as the result.

You can call this function with the value of t to get the amount of water in the pool after t hours. For example, to find the amount of water in the pool after 5 hours, you would call the function `calculate_water_in_pool(5)` and it would return the result.