Uppose you send about 12 text messages a day, and your older sister sends more text messages than you do. Together, you send a total of about 26 messages per day. About how many text messages does she send a day? Write an equation and solve for the unknown value

In order to get your answer, take the number of text messages you send each day (12) and subtract it from the number you and your sister send (26). When you get the answer from subtracting both of these numbers, take the answer from your subtraction and add it to the number of text messages that you send a day (12).