Question

Two cell phone companies have different rate plans. Runfast has monthly charges $10 plus $4 per gig of data. B A &D’s monthly charge is $6 plus $6 per gig of data. Your task is to determine under what circumstances each company has the better pricing. You will derive and solve a set of equations, graph those equations, and evaluate the meanings for these events. Don’t worry; I have a series of questions to guide you through the process. Good luck!

1. (1pt) Determine the equation for the monthly charges for Runfast and B A&D.

Runfast= ______________________

BA&D=________________________

2. (4 pts)Use your mathematical skill to solve this system of equations using the substitution method. (show your work here)

Answer 1

Let x be the number of gb used.

Question (1):
Runfast = 10 + 4x
BA&D= 6 + 6x

Question (2):
10 + 4x = 6 + 6x
2x = 4
x = 2

Both companies will cost the same if you use 2 Gb of data.
BA&D will be cheaper if you use less than 2 Gb of data.
Runfast will be cheaper if you use more than 2 Gb of data.