for her birthday, Sarah's parents got her a new phone. the phone's plan costs$59.99 a month and allows for unlimited calls, unlimited web access, and 100 text messages a month. in addition, each text message over the 100 included with the plan is $0.10. if Sarah's parents budget $78.00 a month for her cell phone bill, what is the maximum number of text messages that she can send in one month.