document.write( "Question 417064: Doreen is a chemist. she needs to prepare 24 ounces of a 7% solution. Find the amount of 12% solution and the amount of a 6% solution she should mix to get this solution?
\n" ); document.write( "Amount of 12%:
\n" ); document.write( "Amount of 6%: \n" ); document.write( "

Algebra.Com's Answer #292069 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"a\"$ = ounces of 6% solution needed
\n" ); document.write( "Let $\"b\"$ = ounces of 12% solution needed
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\n" ); document.write( "given:
\n" ); document.write( "(1) $\"a+%2B+b+=+24\"$
\n" ); document.write( "(2) $\"+%28.06a+%2B+.12b%29%2F24+=+.07+\"$
\n" ); document.write( "---------
\n" ); document.write( " $\".06a+%2B+.12b+=+.07%2A24\"$
\n" ); document.write( " $\".06a+%2B+.12b+=+1.68+\"$
\n" ); document.write( "(2) $\"+6a+%2B+12b+=+168+\"$
\n" ); document.write( "Multiply both sides of (1) by $\"6\"$
\n" ); document.write( "and subtract from (2)
\n" ); document.write( "(2) $\"+6a+%2B+12b+=+168+\"$
\n" ); document.write( "(1) $\"-6a+-+6b+=+-144\"$
\n" ); document.write( " $\"6b+=+24\"$
\n" ); document.write( " $\"b+=+4\"$
\n" ); document.write( "and
\n" ); document.write( " $\"a+=+24+-+4\"$
\n" ); document.write( " $\"a+=+20\"$
\n" ); document.write( "She needs 20 ounces of 6% solution and
\n" ); document.write( "4 ounces of 12% solution \n" ); document.write( "

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