What you need to do first is solve for the message cost. So to do that do 75-50=25 (because that's the difference cost between them both)
25, which as I explained, is the difference between those numbers that give us the cost difference. 75 cents.
75/25, meaning the extra cost and the text message difference. That equals 3.
3 cents per message.
The monthly fee is 50*3=150, and 150 is the equal of the 50 text messages. Don't forget we are using cents. So its a $1.50
$35-$1.5=X. X is the monthly fee
