document.write( "Question 414986: How many quarts of pure anitifreeze must be added to 4 quarts of a 20% antifreeze solution to obtain a 50% antifreez solution? \n" ); document.write( "

Algebra.Com's Answer #291008 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"x\"$ = quarts of pure antifreeze needed
\n" ); document.write( " $\".2%2A4+=+.8\"$ = pure antifreeze in 20% solution
\n" ); document.write( " $\"+%28x+%2B+.8%29+%2F+%28x+%2B+4%29+=+.5\"$
\n" ); document.write( " $\"+x+%2B+.8+=+.5%2A%28x+%2B+4%29+\"$
\n" ); document.write( " $\"x+%2B+.8+=+.5x+%2B+2\"$
\n" ); document.write( " $\".5x+=+1.2\"$
\n" ); document.write( " $\"x+=+2.4\"$
\n" ); document.write( "2.4 quarts of pure antifreeze must be added
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28x+%2B+.8%29+%2F+%28x+%2B+4%29+=+.5\"$
\n" ); document.write( " $\"+%282.4+%2B+.8%29+%2F+%282.4+%2B+4%29+=+.5\"$
\n" ); document.write( " $\"3.2%2F6.4+=+.5\"$
\n" ); document.write( " $\"3.2+=+3.2\"$
\n" ); document.write( "OK \n" ); document.write( "

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