document.write( "Question 869180: Joel has twice as many CDs as Mariella has. Subtracting 7 from the number of CD's Joel has and dividing by 3 equals the number of CDs blake has. If Blake has 25 CDs how many CDs does Mariella have? \n" ); document.write( "

Algebra.Com's Answer #524073 by XilliX(3) $\"\"$ $\"About$

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We can write each of the statements as an equation
\n" ); document.write( "1. Joel $\"j\"$ has twice the number of CDs as Mariella $\"m\"$ , hence
\n" ); document.write( "   $\"j=2m\"$

\n" ); document.write( "2. Joel's number of CD's - 7 divided by 3 equals the number of CDs Blake $\"b\"$ has:
\n" ); document.write( "   $\"%28j-7%29%2F3=b\"$

\n" ); document.write( "3. Blake has 25 CDs
\n" ); document.write( " $\"b=25\"$
\n" ); document.write( "

\n" ); document.write( "Substituting (3) into (2) gives:
\n" ); document.write( "   $\"%28j-7%29%2F3=25\"$
\n" ); document.write( "   $\"j-7=3x25\"$
\n" ); document.write( "   $\"j-7=75\"$
\n" ); document.write( "   $\"j=75%2B7\"$
\n" ); document.write( "   $\"j=82\"$

\n" ); document.write( "So Joel has got 82 CD's

\n" ); document.write( "Based on equation (1) we can calculate the number of CD's Mariella has:
\n" ); document.write( "   $\"82=2m\"$
\n" ); document.write( "   $\"m=82%2F2\"$
\n" ); document.write( "   $\"m=41\"$
\n" ); document.write( "

\n" ); document.write( "Mariella has 41 CDs
\n" ); document.write( "Joel has 82 CDs
\n" ); document.write( "Blake has 25 CDs \n" ); document.write( "

\n" );