Question

Forrest Lumber uses the function
S(t) = -75t + 600

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?
-8 years
10 years
9 years
8 years

Why this is so difficult for me, I do not know. Hmph

Answer 1

0 = -75t + 600

Answer 2

Thanks :D got it correct