document.write( "Question 410642: a cars radiator contains 12 L of antifreeze at 25% concentration. how many liters must be drained and then replaced by pure antifreeze to bring the concentration to 50% \n" ); document.write( "
Algebra.Com's Answer #288833 by ankor@dixie-net.com(22740)\"\" \"About 
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a cars radiator contains 12 L of antifreeze at 25% concentration.
\n" ); document.write( " how many liters must be drained and then replaced by pure antifreeze to bring the concentration to 50%
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\n" ); document.write( "Let x = amt of 25% solution drained, and amt of pure antifreeze to be added
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\n" ); document.write( ".25(12 - x) + x = .50(12)
\n" ); document.write( "3 - .25x + x = 6
\n" ); document.write( "-.25x + x = 6 - 3
\n" ); document.write( ".75x = 3
\n" ); document.write( "x = \"3%2F.75\"
\n" ); document.write( "x = 4 liters drained, and 4 liters of pure antifreeze added
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\n" ); document.write( "Check this solution in the original mixture equation
\n" ); document.write( ".25(12-4) + 4 = 6
\n" ); document.write( ".25(8) + 4 = 6, confirms our solution of 4 liters \n" ); document.write( "
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