Forrest Lumber uses the function

Question

S(t) = -75t + 375
to determine the salvage value S(t), in dollars, of a table saw t years after its purchase. How long will it take the saw to depreciate completely?

Answer 1

S(t) = -75t + 375

-75t + 375 = 0
-75t = -375
t = 5 years

Answer 2

Forgot to add the reasoning for setting the equation equal to 0.

Since S(t) is the salvage value, to find how many years it will take for the saw to depreciate, you would set the equation to 0.

This is because savage value would equal 0 dollars when an item was fully depreciated.