document.write( "Question 273821: Demtris is 14 years older than Sam. In 9 years he will be twice her age. How old are Demetris and sam? \n" ); document.write( "

Algebra.Com's Answer #199995 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"d\"$ = Demetris's age now
\n" ); document.write( "Let $\"s\"$ = Sam's age now
\n" ); document.write( " $\"d+%2B+9\"$ = Demetri's age in 9 years
\n" ); document.write( " $\"s+%2B+9\"$ = Sam's age in 9 years
\n" ); document.write( "given:
\n" ); document.write( " $\"d+=+s+%2B+14\"$
\n" ); document.write( "(1) $\"d+-+s+=+14\"$
\n" ); document.write( "and
\n" ); document.write( " $\"d+%2B+9+=+2%2A%28s+%2B+9%29\"$
\n" ); document.write( " $\"d+%2B+9+=+2s+%2B+18\"$
\n" ); document.write( "(2) $\"d+-+2s+=+9\"$
\n" ); document.write( "Subtract (2) from (1)
\n" ); document.write( "(1) $\"d+-+s+=+14\"$
\n" ); document.write( "(2) $\"-d+%2B+2s+=+-9\"$
\n" ); document.write( " $\"s+=+5\"$
\n" ); document.write( "and, from (1)
\n" ); document.write( " $\"d+-+5+=+14\"$
\n" ); document.write( " $\"d+=+14+%2B+5\"$
\n" ); document.write( " $\"d+=+19\"$
\n" ); document.write( "Demetri is 19 and Sam is 5
\n" ); document.write( "check:
\n" ); document.write( " $\"d+%2B+9+=+2%2A%28s+%2B+9%29\"$
\n" ); document.write( " $\"19+%2B+9+=+2%2A%285+%2B+9%29\"$
\n" ); document.write( " $\"28+=+2%2A14\"$
\n" ); document.write( " $\"28+=+28\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );