A phone company has a monthly cellular plan where a customer pays a flat monthly fee and then a certain amount of money per minute used for voice and video calling. If a customer uses 410 minutes, the monthly cost will be $71.50. If the customer uses 720 minutes, the monthly cost will be $118.
- ⓐ Find a linear equation for the monthly cost of the cell plan as a function of x, the number of monthly minutes used.
- ⓑ Interpret the slope and y-intercept of the equation.
- ⓒ Use your equation to find the total monthly cost if 687 minutes are used.
OpenStax Precalculus 2e, 2.3 Modeling with Linear Functions, exercise 54