At time x0, water begins to drain steadily out of a bathtub. After seconds, the water in the tub is cm deep. After seconds, the tub is empty. Write a linear function rule that models the depth of water in the tub y after any number of seconds x. Suppose the drain rate of another bathtub is cm/second. Use pencil and paper. Describe a "draining race" between these two tubs. Be sure to include the initial depths of water in the tubs and which tub wins.