Question

Julia’s text messaging plan changes 15¢ for each message over 300 in addition to a $7 base charge. If she owes $15.10 for text messaging in the month of june, how many text messages did she send that month?

Answer 1

We are given that the charge for text messages over 300 is 15 cents plus $7 base charge. This means that if "x" is the number of text messages over 300 then the cost is defined by the following equation:

`C=0.15x+7`

Now, we are given that she owes $15.10, therefore, to determine the number of text messages "x" we need to set "C = 15.10":

`15.10=0.15x+7`

Now, we solve for "x". First, we subtract 7 from both sides:

`15.10-7=0.15x`

Solving the operations:

`8.10=0.15x`

Now, we divide both sides by 0.15:

`(8.10)/(0.15)=x`

Solving the operations:

`54=x`

Therefore, there are 54 text messages over the 300. The total number of text messages is then:

`300+54=354`

She sent 354 text messages.