At the end of a snow storm, Audrey saw there was a lot of snow on her front lawn. The temperature increased and the snow began to melt at a steady rate. There was a depth of 10 inches of snow on the lawn when the storm ended and then it started melting at a rate of 2 inches per hour. Write an equation for S, S, in terms of t, t, representing the depth of snow on Audrey's lawn, in inches, t hours after the snow stopped falling.