document.write( "Question 302230: The cost of a long distance telephone call is determined by a flat fee for the first 5 minutes and a fixed amount for each additional minute. If a 15 minute telephone call costs $3.25 and a 23 minute call costs $5.17, find the cost of a 30 minute call. \n" ); document.write( "
Algebra.Com's Answer #216795 by ankor@dixie-net.com(22740)\"\" \"About 
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The cost of a long distance telephone call is determined by a flat fee for the
\n" ); document.write( "first 5 minutes and a fixed amount for each additional minute.
\n" ); document.write( "If a 15 minute telephone call costs $3.25 and a 23 minute call costs $5.17, find the cost of a 30 minute call.
\n" ); document.write( ":
\n" ); document.write( "Let x = flat fee for 5 min
\n" ); document.write( "Let y = per minute fee after 5 min
\n" ); document.write( ":
\n" ); document.write( "cost of 15 min call equation
\n" ); document.write( " x + 10y = 3.25
\n" ); document.write( ":
\n" ); document.write( "Cost of 23 min call equation
\n" ); document.write( " x + 18y = 5.17
\n" ); document.write( ":
\n" ); document.write( "Subtract the 1st equation from the 2nd equation
\n" ); document.write( "x + 18y = 5.17
\n" ); document.write( "x + 10y = 3.25
\n" ); document.write( "------------------subtraction eliminates x, find y
\n" ); document.write( "8y = 1.92
\n" ); document.write( "y = \"1.92%2F8\"
\n" ); document.write( "y = $.24 for each minute over five minutes
\n" ); document.write( "Find y
\n" ); document.write( "x + 10y = 3.25
\n" ); document.write( "x + 10(.24) = 3.25
\n" ); document.write( "x + 2.40 = 3.25
\n" ); document.write( "x = 3.25 - 2.40
\n" ); document.write( "x = $.85 flat fee for 1st five minutes
\n" ); document.write( ":
\n" ); document.write( "Cost for a 30 min call
\n" ); document.write( "C = .85 + 25(.24)
\n" ); document.write( "C = $6.85 \n" ); document.write( "
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