a cell phone company offers a contract for which the cost C, in dollars, of t minutes of telephoning is given by C=0.25(t-600)+$62.95, where it is assured that t is greater than or equal to 600 minutes. what times will keep costs between $104.45 and $141.95?
For cost = $104.45
0.25(t-600)+62.95 = 104.45
(t-600) = (104.45-62.95)/0.25
t=766 minutes
Repeat the same calculations for cost=$141.95