Answer :
Answer:
The total number of text messages sent was 27.
Step-by-step explanation:
The monthly cost of the cell phone plan, in function of the number of text messages sent(s) and the number of messages received(r), is given by:
[tex]C = 39.95 + 0.15(s + r)[/tex]
In this question, we have that:
[tex]C = 53.45, r = 63[/tex]
We put this into the equation to find the value of s. So
[tex]C = 39.95 + 0.15(s + r)[/tex]
[tex]53.45 = 39.95 + 0.15(s + 63)[/tex]
[tex]0.15s + 9.45 = 13.50[/tex]
[tex]s = \frac{13.50 - 9.45}{0.15}[/tex]
[tex]s = 27[/tex]
The total number of text messages sent was 27.