document.write( "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? \n" ); document.write( "

Algebra.Com's Answer #143031 by jonvaliente(64) $\"\"$ $\"About$

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Set up the inequality:
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\n" ); document.write( "90.20<0.25(t-300)+46.95<120.20
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\n" ); document.write( "Subtracting 46.95 from all terms, we get:
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\n" ); document.write( "43.25<0.25(t-300)<73.25
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\n" ); document.write( "Simplifying the middle term, we get:
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\n" ); document.write( "43.25<0.25t-75<73.25
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\n" ); document.write( "Adding 75 to all terms, we get:
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\n" ); document.write( "118.25<0.25t<148.25
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\n" ); document.write( "Dividing all terms by 0.25, we get:
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\n" ); document.write( " $\"473%3Ct%3C593\"$
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\n" ); document.write( "Therefore, the phone must be used more than 473 minutes but less than 593 minutes for the cost to be within the specified range. \n" ); document.write( "

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