document.write( "Question 1037138: a man is twice as old as his duaghter ten years ago he was three times as old. How old is the daughter? \n" ); document.write( "

Algebra.Com's Answer #651866 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+a+\"$ = man's age now
\n" ); document.write( "Let $\"+b+\"$ = daughter's age now
\n" ); document.write( "------------------------------
\n" ); document.write( "(1) $\"+a+=+2b+\"$
\n" ); document.write( "(2) $\"+a+-+10+=+3%2A%28+b+-+10+%29+\"$
\n" ); document.write( "-------------------------
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+2b+-+10+=+3%2A%28+b+-+10+%29+\"$
\n" ); document.write( "(2) $\"+2b+-+10+=+3b+-+30+\"$
\n" ); document.write( "(2) $\"+b+=+20+\"$
\n" ); document.write( "The daughter is 20
\n" ); document.write( "-----------------
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+a+=+2b+\"$
\n" ); document.write( "(1) $\"+a+=+2%2A20+\"$
\n" ); document.write( "(1) $\"+a+=+40+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+a+-+10+=+3%2A%28+b+-+10+%29+\"$
\n" ); document.write( "(2) $\"+a+-+10+=+3%2A%28+20+-+10+%29+\"$
\n" ); document.write( "(2) $\"+a+-+10+=+30+\"$
\n" ); document.write( "(2) $\"+a+=+40+\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );