Karen is trying to choose a cell phone plan. Company J charges a subscription fee of $30 per month plus $1 per hour of use. Company K charges no monthly fee, but charges $2 for every hour of use.
Karen made the following graph to compare the prices of the two plans.
The lines for Company J and Company K cross at a point. The coordinate (30, 60) is the point at which Company J and Company K cost the same.
What does the point (30, 60) mean? (Hint: What is being graphed on the x-axis? What is being graphed on the y-axis?)
If Karen uses her cell phone for less than 30 minutes a month, which company should Karen choose? Why?
If Karen uses her cell phone for more than 30 minutes a month, which company should Karen choose? Why?