Interpreting a Linear Equation
At 12:00 P.M. the volume of water in a tank started changing steadily over time. The volume V\displaystyle {V} measured in gallons, t\displaystyle {t} minutes after the water volume started to change is given by the equation V=4090020.45t\displaystyle {V}={40900}-{20.45}{t}.

The equation tells us that the volume of water in the tank was initially gallons, and that the volume is by .