The phone company Ringular has a monthly cellular plan where a customer pays a flat monthly fee and then a certain amount of money per minute used on the phone. If a customer uses 300 minutes

Question

The phone company Ringular has a monthly cellular plan where a customer pays a flat monthly fee and then a certain amount of money per minute used on the phone. If a customer uses 300 minutes, the monthly cost will be $62. If the customer uses 570 minutes, the monthly cost will be $89.

A) Find an equation in the form  where  is the number of monthly minutes used and  is the total monthly of the Ringular plan.

Answer: 

B) Use your equation to find the total monthly cost if 698 minutes are used.

(Answer: If 698 minutes are used, the total cost will be __________ dollars.)

Answer 1

y = mx + b

(300, 62)

(570,89)

the slope is (89 - 62)/(570-300) = 27/270 = 1/10

62 = (1/10)(300) + b

62 = 30 + b

b = 32

y = (1/10)x + 32

for x=698, y = 101.8