Bob climbs a mountain, but starts below sea level. He climbs the same number of feet each hour. If the function showing his elevation for any hour is y = 850x - 325, what elevation, in feet, did he start at?

A.

325

B.

850

C.

-850

D.

-325

We are given the function y = 850x - 325 in which y is the elevation and x is the number of hours hence time is a function of elevation. In this case, with the given equation, the person starts at - 325 since when x is zero, y is - 325.