document.write( "Question 1038595: Please help me solve this equation:Daniel is three times as old as kathryn. seven years ago, daniel was five times as old as kathryn. How are old they? \n" ); document.write( "

Algebra.Com's Answer #653301 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+d+\"$ = Daniel's age now
\n" ); document.write( "Let $\"+k+\"$ = Kathryn's age now
\n" ); document.write( "-------------------------------
\n" ); document.write( "(1) $\"+d+=+3k+\"$
\n" ); document.write( "(2) $\"+d+-+7+=+5%2A%28+k+-+7+%29+\"$
\n" ); document.write( "---------------------------
\n" ); document.write( "This is 2 equations and 2 unknowns,
\n" ); document.write( "so it's solvable
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+3k+-+7+=+5%2A%28+k+-+7+%29+\"$
\n" ); document.write( "(2) $\"+3k+-+7+=+5k+-+35+\"$
\n" ); document.write( "(2) $\"+2k++=+35+-+7+\"$
\n" ); document.write( "(2) $\"+2k+=+28+\"$
\n" ); document.write( "(2) $\"+k+=+14+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+d+=+3%2A14+\"$
\n" ); document.write( "(1) $\"+d+=+42+\"$
\n" ); document.write( "---------------------
\n" ); document.write( "Daniel is 42
\n" ); document.write( "Kathryn is 14
\n" ); document.write( "---------------------
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+d+-+7+=+5%2A%28+k+-+7+%29+\"$
\n" ); document.write( "(2) $\"+42+-+7+=+5%2A%28+14+-+7+%29+\"$
\n" ); document.write( "(2) $\"+35+=+5%2A7+\"$
\n" ); document.write( "(2) $\"+35+=+35+\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );