I have been out of high school since 1993 and have gotten a little rusty.

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, 8, 6, and 10 years.

Just set your linear equation equal to 0 and solve for t.

-75t+600=0

-8 is out because we can not have negative years.

Thanks for your help and I give you a five