document.write( "Question 387104: John is two times older than Mary. Mary is three times younger than Steve. How old is Steve if he is 3 years older than John? \n" ); document.write( "

Algebra.Com's Answer #273631 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
given:
\n" ); document.write( "(1) $\"j+=+2m\"$
\n" ); document.write( "(2) $\"s+=+3m\"$
\n" ); document.write( "(3) $\"s+=+j+%2B+3\"$
\n" ); document.write( "This is 3 equations and 3 unknowns, so it's solvable
\n" ); document.write( "-------------
\n" ); document.write( "By substituting (1) into (2):
\n" ); document.write( " $\"m+=+j%2F2\"$
\n" ); document.write( "(2) $\"s+=+%283%2F2%29%2Aj\"$
\n" ); document.write( " $\"j+=+%282%2F3%29%2As\"$
\n" ); document.write( "Put this into (3):
\n" ); document.write( " $\"s+=+%282%2F3%29%2As+%2B+3\"$
\n" ); document.write( " $\"3s+=+2s+%2B+9\"$
\n" ); document.write( " $\"s+=+9\"$
\n" ); document.write( "Steve is 9 years old
\n" ); document.write( "check answer:
\n" ); document.write( " $\"j+=+%282%2F3%29%2As\"$
\n" ); document.write( " $\"j+=+%282%2F3%29%2A9\"$
\n" ); document.write( " $\"j+=+6\"$
\n" ); document.write( "and
\n" ); document.write( " $\"j+=+2m\"$
\n" ); document.write( " $\"m+=+j%2F2\"$
\n" ); document.write( " $\"m+=+3\"$
\n" ); document.write( "These values check OK \n" ); document.write( "

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