Question

For his phone service, Hong pays a monthly fee of $30, and he pays an additional $0.07 per minute of use. The least he has been charged in a month is $124.92.

What are the possible numbers of minutes he has used his phone in a month?
Use m for the number of minutes, and solve your inequality for m.

Answer 1

First, let's set up the equation

· We know the least total he's got in one month is $124.92

· In that one month, he was charged an additional $30 dollar fee.

· During the time he uses his phone, he is charged $0.07 per unknown minutes (which we can consider 'm').

It would look like this;

30 + 0.07m = 124.92

where $30 is the additional fee

$0.07 is the money he is charged per unknown minutes otherwise known as 'm'

$124.92 is the total of that whole month (which has been the least amount of money he used)

So now we solve for m:

30 + 0.07m = 124.92

-30 -30(get rid of any constants first by performing the inverse operation of addition, subtraction)

0.07m = 94.92

/0.07 /0.07 (isolate 'm' by applying the inverse operation of multiplication, division)

m = 1,356 minutes