SOLUTION: A cellar phone company offers a contract for which the cost C in dollars, of it t minutes of the telephone is given by C=0.25 (t-300)+46.95, when it assumed that

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Question 190543: A cellar phone company offers a contract for which the cost C in dollars, of it t minutes of the telephone is given by C=0.25 (t-300)+46.95, when it assumed that > 300 mintues. what times will keep the costs between 90.20 and 120.20?
Answer by jonvaliente(64) (Show Source):
You can put this solution on YOUR website!
Set up the inequality:
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90.20<0.25(t-300)+46.95<120.20
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Subtracting 46.95 from all terms, we get:
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43.25<0.25(t-300)<73.25
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Simplifying the middle term, we get:
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43.25<0.25t-75<73.25
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Adding 75 to all terms, we get:
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118.25<0.25t<148.25
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Dividing all terms by 0.25, we get:
.

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Therefore, the phone must be used more than 473 minutes but less than 593 minutes for the cost to be within the specified range.

SOLUTION: A cellar phone company offers a contract for which the cost C in dollars, of it t minutes of the telephone is given by C=0.25 (t-300)+46.95, when it assumed that > 300 mintues. wha