Jan spends part of her year as a member of a gym. she then finds a better deal at another gym, so she cancels her membership with the first gym and spends the rest of the year with the second gym.

Tim's phone service charges $26.39 plus an additional $0.21 for each text message sent per month. if tim's phone bill was $31.64, which equation could be used to find how many text messages, x, tim sent last month?