Answer:

Explanation:
Since the increase is the same each year, we can model this situation by a linear function, in the following format:

In which w(t) is the water level after t years, w(0) is the initial water level and a is the yearly increase.
The initial water level of the lake was 800 meters
This means that

The water level increases by 1 m each year.
This means that

So

