College algebra

Question

The phone Company next fell has a monthly cellular plan where a customer pays a flat monthly fee and a certain amount of money per minute used on the phone. Customer uses 440 minutes, the monthly cost will be tonight $246. If the customer uses 840 minutes, the monthly cost will be $446.

A) Find an equation in the form of y=mx+b, Where X is the number of monthly minutes used and why is the total monthly cost of the next fell plan.

B) Use your equation to find the total monthly cost 824 minutes are used

Answer 1

F + 440M = 246

F + 840 = 446

400M = 200

M = 50 cents per minute charge = 1/2 dollar

F = 245-440(1/2) = $25 fixed monthly charge

C(m) = 25 + m/2

y = (1/2)x + 25 where x = minutes used and 25 = monthly charge or y intercept = b and 1/2 = m = slope

C(24) = 25 + 24/2 = 25 +12 = $37 for 24 minutes