document.write( "Question 833100: For extremely cold temperatures, an automobile manufacturer recommends that a 80% antifreeze and 20% water mix be used in the cooling system of a car. How many quarts of pure (100%) antifreeze and 50% antifreeze and 50% water mix should be combined to make 15 quarts of 80% antifreeze and 20% water mix? \n" ); document.write( "
Algebra.Com's Answer #502443 by ankor@dixie-net.com(22740)\"\" \"About 
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\n" ); document.write( "For extremely cold temperatures, an automobile manufacturer recommends that a 80% antifreeze and 20% water mix be used in the cooling system of a car.
\n" ); document.write( " How many quarts of pure (100%) antifreeze and 50% antifreeze and 50% water mix should be combined to make 15 quarts of 80% antifreeze and 20% water mix?
\n" ); document.write( ":
\n" ); document.write( "Let x = amt of pure antifreeze
\n" ); document.write( "then
\n" ); document.write( "(15-x) = amt of 50:50 mix required
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\n" ); document.write( "An amt of antifreeze equation
\n" ); document.write( ".50(15-x) + x = .80(15)
\n" ); document.write( "7.5 - .5x + 1x = 12
\n" ); document.write( ".5x = 12 - 7.5
\n" ); document.write( ".5x = 4.5
\n" ); document.write( "x = 4.5/.5
\n" ); document.write( "x = 9 quarts of pure antifreeze required
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