algebra
posted by tina .
a barrel contains 163 gallons of water and is being drained at a constant rate of gallons per hour write an equation that models the number of gallons g after t hours

You omitted the units for the rate of drawing,
Anyway, drwls answered the "same" question here
http://www.jiskha.com/display.cgi?id=1342753988
Just make the necessary changes. 
Math function