For her phone service, donna pays a monthly fee of 16, and she pays an additional $0.05 per minute use. the least she has been charged in a month is $76.45. what are the possible numbers of minutes she has used her phone in a month?

1209 minutes

Step-by-step explanation:

To solve this problem we must propose an equation that models the cost of the telephone service based on the number of minutes used x.

If we call C at cost then we know that the cost is composed of a fixed cost of 16 and a cost that varies depending on the number of minutes used (0.05x)

So:

We know that the cost in one month was $ 76.45. Now we substitute this value in the equation and solve for the variable x.

m= 1209 minutes..

Step-by-step explanation:

Let m represent the number of minutes.

Donna pays a monthly fee of 16, and she pays an additional $0.05 per minute use. the least she has been charged in a month is $76.45

The equation becomes:

16+m*0.05=$76.45

Subtract 16 from both sides:

16-16+m*0.05=$76.45-16

0.05m= $60.45

Divide 0.05 from both sides.

0.05m/0.05= $60.45/0.05

m= 1209 minutes..

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!