The cell phone plan from Company C costs $15 per month, plus $12 per gigabyte for data used. The plan from Company D costs $75 per month, with unlimited data. Rule C gives the monthly cost, in dollars, of using gigabytes of data on Company C’s plan. Rule gives the monthly cost, in dollars, of using gigabytes of data on Company D’s plan. Sara wants to know what company to go with if her average gigabyte usage is 7 gigabytes per month. Explain which plan she should use, Company C or D? Make sure you support your choice with mathematical evidence.

Company D
Step by step explanation:
First we need to figure out how much money it would be for company C. If it is $15 per month and $12 per gigabytes used. We would set up and equation that would look like 15 + 12g (g= gigabyte used) and in this case we would substitute G for 7 which would look like 15 +12(7), 15 + 84= $99. Meaning that if Sara were to go with Company c she would be spending $99. Not we would solve for Company D, there is not much to solve for Company D considering that it is only $75 a month and includes unlimited data. If Sara were to go with Company C she would be spending $24 more than sue if she were to choose company D.
Hope this helps!
Please tell me if I am incorrect, I enjoy learning from my mistakes!
Good luck❤️

The solution to the system of equations (-2,2)