Question

A phone company 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 490 minutes, the monthly cost will be $93.50. If the customer uses 880 minutes, the monthly cost will be $152.

Answer 1

Answer: the cost per minute of call made in a month is $0.15

the flat monthly fee that the customer pays is $20

Explanation:

Let x represent the cost per minute of call made in a month.

Let y represent the flat monthly fee that the customer pays.

If a customer uses 490 minutes, the monthly cost will be $93.50. This means that

490x + y = 93.50 - - - - - - - - - -1

If the customer uses 880 minutes, the monthly cost will be $152. This means that

880x + y = 152 - - - - - - - - 2

Subtracting equation 1 from equation 2, it becomes

- 390x = - 58.5

x = - 58.5/ - 390

x = 0.15

Substituting x = 0.15 into equation 1, it becomes

490(0.15) + y = 93.50

73.5 + y = 93.5

y = 93.5 - 73.5 = 20