Question

By your cell phone contract, you pay a monthly fee plus $0.06 for each minute you spend on the phone. In one month, you spent 280 minutes over the phone, and had a bill totaling $34.80 Let x be the number of minutes you spend on the phone in a month, and let y be your total cell phone bill for that month, in dollars. Use a linear equation to model your monthly bill based on the number of minutes you spend on the phone a. A) point-slope equation to model this is ( )B) If you spend 180 minutes on the phone in a month, you would be billed ( ) C. If your bill was $45.00 one month, you must have spent minutes on the phone in that month Note ( )

Answer 1

Answer:

A) The linear equation model: y = 0.06x + 18

B) If you spend 180 minutes on the phone in a month, you would be billed $28.8

C) If your bill was $45.00 one month, you must have spent 450 minutes on the phone in that month

Explanations:

x represents the number of minutes spent in a month

y = total cell phone charge for the month

Let c represent the monthly fee

The equation of a line is given as

y = mx + c

Let m represent the charge per minute

m = 0.06

y = 0.06x + c...........(*)

In one month, you spent 280 minutes over the phone, and had a bill totaling $34.80

x = 280 minutes

y = 34.80

Substitute these values into equation (*)

34.80 = 0.06(280) + c

34.80 = 16.8 + c

c = 34.80 - 16.8

c = 18

The monthly fee = $18

A) The linear equation model is therefore:

y = 0.06x + 18

B) If you spend 180 minutes on the phone in a month, how much will you be billed?

y = 0.06x + 18

x = 180

y = 0.06(180) + 18

y = 10.8 + 18

y = 28.8

If you spend 180 minutes on the phone in a month, you would be billed $28.8

C) If your bill was $45, find the number of minutes spent on phone

Substitute y = 45 into the linear equation gotten

y = 0.06x + 18

45 = 0.06x + 18

0.06x = 45 - 18

0.06x = 27

x = 27/0.06

x = 450

If your bill was $45.00 one month, you must have spent 450 minutes on the phone in that month