document.write( "Question 345458: How many liters of pure acid must be mixed with 20 liters of a 15% acid solution to get a 20% mixture? \n" ); document.write( "

Algebra.Com's Answer #247056 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"x\"$ = liters of pure acid needed
\n" ); document.write( "In words:
\n" ); document.write( "(total liters of acid)/(total liters of solution) = 20%
\n" ); document.write( "given:
\n" ); document.write( "acid already in solution: $\".15%2A20+=+3\"$ liters
\n" ); document.write( "-------------
\n" ); document.write( " $\"%28x+%2B+3%29%2F%2820+%2B+x%29+=+.2\"$
\n" ); document.write( " $\"x+%2B+3+=+4+%2B+.2x\"$
\n" ); document.write( " $\".8x+=+1\"$
\n" ); document.write( " $\"x+=+1.25\"$ liters
\n" ); document.write( "1.25 liters of acid are needed
\n" ); document.write( "check:
\n" ); document.write( " $\"%28x+%2B+3%29%2F%2820+%2B+x%29+=+.2\"$
\n" ); document.write( " $\"%281.25+%2B+3%29%2F%2820+%2B+1.25%29+=+.2\"$
\n" ); document.write( " $\"4.25%2F21.25+=+.2\"$
\n" ); document.write( " $\"4.25+=+.2%2A21.25\"$
\n" ); document.write( " $\"4.25+=+4.25\"$
\n" ); document.write( "OK \n" ); document.write( "

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