Aforest has 800 pine trees, but a disease is introduced that kills -- of the pine trees in the forest every year.
write a function that gives the number of pine trees remaining p(t) in the forest t years after the disease is
introduced.

P(t)=800-x(t)

Step-by-step explanation:

Assuming that no other pine tree naturally grows

Let the number of pine trees killed every year be x

Remaining trees after 1 year will be 800-x

After two years, remaining trees will be 800-2x

After three years, remaining trees will be 800-3x

The trend here is

P(t)=800-x(t) hence after 5 years

P(5)=800-5t and so on

Therefore, the function is

P(t)=800-x(t)

what is a pre-existing condition claus?

means if you're already damaged some way when you take out a medical insurance you will not get full compensation for that injury that you already have.