Question

Forrest Lumber uses the function
S(t) = -105t + 630

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?
7 years
5 years
6 years
-6 years

Answer 1

For it to depreciate completely, S(t) must be equal to 0

Answer 2

So you have:

S(t) = -105t + 630
0 = -105t + 630

Can you find t now?

Answer 3

no idk

Answer 4

To find t, you need to isolate t.

So we have 0 = -105t + 630

We need to do something about 630. What to do?

Answer 5

idk subtract

Answer 6

or add

Answer 7

divide.

Answer 8

s(t)=-105t+630
-105t=s(t)-630
t=(630-s(t)/105

Answer 9

t=s(t)-630/105

Answer 10

divide this and u get the answer.