document.write( "Question 628541: At the local fast food restaurant, 5 cokes and 7 orders of french fries cost $7.25, while 4 cokes and 5 orders od french fries cost $5.50. Then what are the prices of a single coke and a single order of fries? \n" ); document.write( "
Algebra.Com's Answer #395724 by nerdybill(7384)\"\" \"About 
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At the local fast food restaurant, 5 cokes and 7 orders of french fries cost $7.25, while 4 cokes and 5 orders od french fries cost $5.50. Then what are the prices of a single coke and a single order of fries?
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\n" ); document.write( "Let c = cost of single coke
\n" ); document.write( "and f = cost of single french fry
\n" ); document.write( "then our system of equations is
\n" ); document.write( "5c + 7f = 7.25
\n" ); document.write( "4c + 5f = 5.50
\n" ); document.write( ".
\n" ); document.write( "multiply top eq by 4 and bottom eq by -5 then add together:
\n" ); document.write( " 20c + 28f = 29
\n" ); document.write( "-20c - 25f = -27.5
\n" ); document.write( "-------------------
\n" ); document.write( " 3f = 1.50
\n" ); document.write( " f= .50 (cost of single order of french fry)
\n" ); document.write( ".
\n" ); document.write( "cost of single coke:
\n" ); document.write( "plug above into:
\n" ); document.write( "4c + 5f = 5.50
\n" ); document.write( "4c + 5(.50) = 5.50
\n" ); document.write( "4c + 2.50 = 5.50
\n" ); document.write( "4c = 3.00
\n" ); document.write( "c = .75\r
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