In this lesson, we learn how to solve a word problem involving different rates for cell phone use using two variables and two linear equations. We’re given Tim’s cell phone usage and charges for May and June and we’re asked to find the cost per minute during peak hours. We let X be the cost per minute during peak hours and Y be the cost per minute during non-peak hours. By setting up two equations and using the addition method, we find that the cost per minute during peak hours is 22 cents, while the cost per minute during non-peak hours is 15 cents. We also learn a trick to simplify the problem by dividing common factors.
Shows how to solve a word problem involving different rates for cell phone use using 2 variables and 2 linear equations.
More free YouTube videos by Julie Harland are organized at http://yourmathgal.com