document.write( "Question 691607: zelma is eighteen years older than her son. she was three times as old as he was oneyear ago. how old are they now? \n" ); document.write( "

Algebra.Com's Answer #426782 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+a+\"$ = her age now
\n" ); document.write( "Let $\"+b+\"$ = her Son's age now
\n" ); document.write( " $\"+a-1+\"$ = her age 1 year ago
\n" ); document.write( " $\"+b-1+\"$ = her Son's age 1 year ago
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+a+=+b+%2B+18+\"$
\n" ); document.write( "(2) $\"+a+-+1+=+3%2A%28+b+-+1+%29+\"$
\n" ); document.write( "-----------------------
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+b+%2B+18+-+1+=+3%2A%28+b+-+1+%29+\"$
\n" ); document.write( "(2) $\"+b+%2B+17+=+3b+-+3+\"$
\n" ); document.write( "(2) $\"+2b+=+20+\"$
\n" ); document.write( "(2) $\"+b+=+10+\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+a+=+b+%2B+18+\"$
\n" ); document.write( "(1) $\"+a+=+10+%2B+18+\"$
\n" ); document.write( "(1) $\"+a+=+28+\"$
\n" ); document.write( "Zelma is 28
\n" ); document.write( "Her Son is 10
\n" ); document.write( "-----------
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+a+-+1+=+3%2A%28+b+-+1+%29+\"$
\n" ); document.write( "(2) $\"+28+-+1+=+3%2A%28+10+-+1+%29+\"$
\n" ); document.write( "(2) $\"+27+=+3%2A9+\"$
\n" ); document.write( "(2) $\"+27+=+27+\"$
\n" ); document.write( "OK\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );