The following situation can be modeled by a linear function. What isthe equation for the linear function and use it to answer the given question. A snowplow has maximum speed of

40 miles per hour on a dry highway. Its maximum speed decreases by 1.7 miles per hour for every inch of snow on the highway. According to this model, at what snow depth will the snow plow be unable to move?

The equation used to model this situation is

nothing , where s is the maximum speed of the snowplow in miles per hour and d is the snow depth in inches.