SOLUTION: a cellular phone company offers a contract for which the cost C, in dollars, of t minutes of telephoning is given by c = 0.25(t-300) + 53.95, where it is assumed the t is >= or equ

Algebra ->  Inequalities -> SOLUTION: a cellular phone company offers a contract for which the cost C, in dollars, of t minutes of telephoning is given by c = 0.25(t-300) + 53.95, where it is assumed the t is >= or equ      Log On


   

Question 149916: a cellular phone company offers a contract for which the cost C, in dollars, of t minutes of telephoning is given by c = 0.25(t-300) + 53.95, where it is assumed the t is >= or equal to 300 minutes. What times will keep cost between $93.20 and $127.20?
For the cost to be between $93.20 and $127.20, the telehoning time must be between _____ minutes and _____ minutes.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
a cellular phone company offers a contract for which the cost C, in dollars, of t minutes of telephoning is given by c = 0.25(t-300) + 53.95, where it is assumed the t is >= or equal to 300 minutes. What times will keep cost between $93.20 and $127.20?
For the cost to be between $93.20 and $127.20, the telehoning time must be between _____ minutes and _____ minutes.
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93.20 <= 0.25(t-300) + 53.95 <= 127.20
Solve the inequality for "t":
1st: subtract 53.95 all along the line of the inequality.
2nd: divide by 0.25 all along the line
3rd: add 300 all along the line to see the solution.
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Cheers,
Stan H.