document.write( "Question 596187: Larry has 66 music CDs. He has 2 times as many rock CDs as country CDs. He has
\n" ); document.write( "3 times as many rock CDs as hip-hop CDs.
\n" ); document.write( "How many rock CDs does Larry have? Please show me the steps. \n" ); document.write( "

Algebra.Com's Answer #377579 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+a+\"$ = number of country CD's
\n" ); document.write( "Let $\"+b+\"$ = number of rock CD's
\n" ); document.write( " $\"+b+=+2a+\"$
\n" ); document.write( " $\"+c+\"$ = number of hip-hop CD's
\n" ); document.write( " $\"+b+=+3c+\"$
\n" ); document.write( "----------------------------
\n" ); document.write( " $\"+a+%2B+b+%2B+c+=+66+\"$
\n" ); document.write( " $\"+b+=+2a+\"$
\n" ); document.write( " $\"+a+=+b%2F2+\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+b+=+3c+\"$
\n" ); document.write( " $\"+c+=+b%2F3+\"$
\n" ); document.write( "-----------
\n" ); document.write( "By substitution:
\n" ); document.write( " $\"+b%2F2+%2B+b+%2B+b%2F3+=+66+\"$
\n" ); document.write( "Multiply both sides by $\"6\"$
\n" ); document.write( " $\"+3b+%2B+6b+%2B+2b+=+396+\"$
\n" ); document.write( " $\"+11b+=+396+\"$
\n" ); document.write( " $\"+b+=+36+\"$
\n" ); document.write( "and, since
\n" ); document.write( " $\"+a+=+b%2F2+\"$
\n" ); document.write( " $\"+a+=+36%2F2+\"$
\n" ); document.write( " $\"+a+=+18+\"$
\n" ); document.write( "also,
\n" ); document.write( " $\"+c+=+b%2F3+\"$
\n" ); document.write( " $\"+c+=+36%2F3+\"$
\n" ); document.write( " $\"+c+=+12+\"$
\n" ); document.write( "Larry has 36 rock CD's
\n" ); document.write( "check:
\n" ); document.write( " $\"+a+%2B+b+%2B+c+=+66+\"$
\n" ); document.write( " $\"+18+%2B+36+%2B+12+=+66+\"$
\n" ); document.write( " $\"+66+=+66+\"$
\n" ); document.write( "OK \n" ); document.write( "

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