Question

A. Julie gets a prepaid cell phone. Initially she has a $40.00 balance on the phone. Each minute of talking cost $0.15Find the value of x that makes f(x)=0, and explain its meaning in terms of the cell phone.

Answer 1

Given that,

Julie gets a prepaid cell phone. Initially she has a $40.00 balance on the phone.

Each minute of talking cost $0.15.

To find the value of x that makes f(x)=0.

Let x be the number of munites of talking.

we know that each minute of talking cost $0.15,

we get the equation as,

`f(x)=40-0.15x`

To find the value of x when f(x)=0,

Substitute f(x)=0, we get

`40-0.15x=0`
`0.15x=40`

`x=(40)/(0.15)`

`x=266.67`

Answer is: x=266.67

It means that with $40.00 balance, Julie can speak upto 266.67 minutes.