they charge $30 per month as a base so that is y
They also charge $0.25 per text message, this is x
so $0.25x+$30y=$59.50
first subtract 30 from both sides to get x alone
$0.25x=$29.50
To find amount of text messages sent, we have to divide
$29.50/$.25
29.50/.25=118
This person sent 118 text messages