In a previous lesson, you met the Williams family, who took a road trip to visit relatives for the holidays. Mrs. Williams drives at an average speed of 60 miles per hour. You used a table to represent the situation where Mrs. Williams drove for x hours and covered a distance of y miles.

Now, let’s consider the situation where the Williams family is coming home from visiting relatives. Mrs. Williams has to drive 350 miles in order to get home. Even though there is road construction, the family still drives at a constant rate; however, it takes them longer to drive home than it did to get to their relatives' house. Shonda Williams was bored, so she kept track of how many miles, y, remained until they got home after a certain amount of time, x, had passed. Shonda’s data appears in the table below.

Use the interactive in the next section to help you determine the slope of the function representing the Williams family’s return trip home.