document.write( "Question 661367: A nurse has 1 liter of a solution that is 10% alcohol. How much pure alcohol must she add to bring it to a solution that contains 25% alcohol? (Hint: A pure alcohol solution contains 100% alcohol) \n" ); document.write( "

Algebra.Com's Answer #411589 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+x+\"$ = liters of pure alcohol she must add
\n" ); document.write( " $\"+.1%2A1+=+.1+\"$ = liters of alcohol in 10% solution
\n" ); document.write( "-------------
\n" ); document.write( " $\"+%28+.1+%2B+x+%29+%2F+%28+1+%2B+x+%29+=+.25+\"$
\n" ); document.write( " $\"+.1+%2B+x+=+.25%2A%28+1+%2B+x+%29+\"$
\n" ); document.write( " $\"+.1+%2B+x+=+.25+%2B+.25x+\"$
\n" ); document.write( " $\"+.75x+=+.15+\"$
\n" ); document.write( " $\"+x+=+.15%2F.75+\"$
\n" ); document.write( " $\"+x+=+.2+\"$
\n" ); document.write( "She must add .2 liters of pure alcohol
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28+.1+%2B+x+%29+%2F+%28+1+%2B+x+%29+=+.25+\"$
\n" ); document.write( " $\"+%28+.1+%2B+.2+%29+%2F+%28+1+%2B+.2+%29+=+.25+\"$
\n" ); document.write( " $\"+.3+%2F+1.2+=+.25+\"$
\n" ); document.write( " $\"+.3+=+.25%2A1.2+\"$
\n" ); document.write( " $\"+.3+=+.3+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

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