A person buys a phone for $82 and signs up for a single-line phone plan with 2000 monthly anytime minutes. The plan costs $115.95 per month. Write an equation that can be used to determine the total cost, C(t), of this phone plan for t months. Then, find the cost for 21 months, assuming that the number of minutes the person uses does not exceed 2000 per month An equation that can be used to determine the total cost, C(t), of the phone plan for t months is C(t) - (Use integers or decimals for any numbers in the expression ) The cost for 21 months, assuming that the number of minutes the person uses does not exceed 2000 per month, is S