Systems Of Equations - Applications

Question

You are choosing between two different cell phone plans. The first plan charges a rate of 23 cents per minute. The second plan charges a monthly fee of $29.95 plus 11 cents per minute. How many minutes would you have to use in a month in order for the second plan to be preferable? 

Answer 1

29.95 + .11M = .23M

.12M = 29.95

M = 29.95/.12 = about 249.6 minutes= 249 minutes & 37.5 seconds when the plans cost the same

use more than 249.6 minutes and the 29.95 +.11M plan is less expensive. Use less than 249.6 minutes per month and the 23 cents plan is cheaper.