Question

Dail-In Communications offers a phone plan that includes a monthly fee and a per minute rate for long
distance. Last month, Jevine made 475 minutes of long distance called and her phone bill was $48.70.
The month before that, she made 518 minutes of long distance calls and her phone bill was $50.85.
Determine the equation that models this plan.

Answer 1

y = mx+b
using the two points,
475m + b = 48.70
518m + b = 50.85
subtract to get
43m = 2.15
m = 0.05
Now you can find b, and finish it off