document.write( "Question 567250: how many liters of pure acid must grace add to four liters of a 10% acid solution to increase the strength to 80% \n" ); document.write( "

Algebra.Com's Answer #366491 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+x+\"$ = liters of pure acid to be added
\n" ); document.write( " $\"+.1%2A4+=+.4+\"$ liters of acid in 10% solution
\n" ); document.write( "---------------
\n" ); document.write( " $\"+%28+x+%2B+.4+%29+%2F+%28+x+%2B+4+%29+=+.8+\"$
\n" ); document.write( " $\"+x+%2B+.4+=+.8%2A%28+x+%2B+4+%29+\"$
\n" ); document.write( " $\"+x+%2B+.4+=+.8x+%2B+3.2+\"$
\n" ); document.write( " $\"+.2x+=+3.2+-+.4+\"$
\n" ); document.write( " $\"+.2x+=+2.8+\"$
\n" ); document.write( " $\"+x+=+14+\"$
\n" ); document.write( "14 liters of pure acid is needed
\n" ); document.write( "check:
\n" ); document.write( " $\"+%28+x+%2B+.4+%29+%2F+%28+x+%2B+4+%29+=+.8+\"$
\n" ); document.write( " $\"+%28+14+%2B+.4+%29+%2F+%28+14+%2B+4+%29+=+.8+\"$
\n" ); document.write( " $\"+14.4+%2F+18+=+.8+\"$
\n" ); document.write( " $\"+14.4+=+.8%2A18+\"$
\n" ); document.write( " $\"+14.4+=+14.4+\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );