document.write( "Question 903242: Ray is 3 times as old as his brother how old is he if in 7 years he will be double his brother's age? \n" ); document.write( "

Algebra.Com's Answer #547880 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+r+\"$ = Ray's age now
\n" ); document.write( "Let $\"+b+\"$ = his brother's age now
\n" ); document.write( "---------------
\n" ); document.write( "(1) $\"+r+=+3b+\"$
\n" ); document.write( "(2) $\"+r+%2B+7+=+2%2A%28+b+%2B+7+%29+\"$
\n" ); document.write( "-------------------------
\n" ); document.write( "(2) $\"+r+%2B+7+=+2b+%2B+14+\"$
\n" ); document.write( "(2) $\"+r+=+2b+%2B+7+\"$
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+3b+=+2b+%2B+7+\"$
\n" ); document.write( "(2) $\"+b+=+7+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+r+=+3b+\"$
\n" ); document.write( "(1) $\"+r+=+3%2A7+\"$
\n" ); document.write( "(1) $\"+r+=+21+\"$
\n" ); document.write( "----------------
\n" ); document.write( "Ray is 21
\n" ); document.write( "His brother is 7
\n" ); document.write( "----------------
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+r+%2B+7+=+2b+%2B+14+\"$
\n" ); document.write( "(2) $\"+21+%2B+7+=+2%2A7+%2B+14+\"$
\n" ); document.write( "(2) $\"+28+=+14+%2B+14+\"$
\n" ); document.write( "(2) $\"+28+=+28+\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );