document.write( "Question 405061: This problem has me thoroughly stumped:\r
\n" ); document.write( "\n" ); document.write( "\"Mary is 3 years older than John. In three years John's age will be 4/5 of Mary's age. What are their ages now?\" \n" ); document.write( "

Algebra.Com's Answer #286182 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"m\"$ = Mary's age now
\n" ); document.write( "Let $\"j\"$ = John's age now
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"m+=+j+%2B+3\"$
\n" ); document.write( "Next is an equation that compares their ages when they are both 3 yrs older
\n" ); document.write( "(2) $\"j+%2B+3+=+%284%2F5%29%2A%28m+%2B+3%29\"$
\n" ); document.write( "------------------------
\n" ); document.write( "(2) $\"5%2A%28j+%2B+3%29+=+4%2A%28m+%2B+3%29\"$
\n" ); document.write( "(2) $\"5j+%2B+15+=+4m+%2B+12\"$
\n" ); document.write( "(2) $\"4m+-+5j+=+3\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"m+-+j+=+3\"$
\n" ); document.write( "Multiply both sides by $\"5\"$ and subtract
\n" ); document.write( "(2) from (1)
\n" ); document.write( "(1) $\"5m+-+5j+=+15\"$
\n" ); document.write( "(2) $\"-4m+%2B+5j+=+-3\"$
\n" ); document.write( " $\"m+=+12\"$
\n" ); document.write( "and, from(1):
\n" ); document.write( " $\"m+=+j+%2B+3\"$
\n" ); document.write( " $\"12+=+j+%2B+3\"$
\n" ); document.write( " $\"j+=+9\"$
\n" ); document.write( "Mary is 12 and John is 9
\n" ); document.write( "check answer:
\n" ); document.write( "(2) $\"j+%2B+3+=+%284%2F5%29%2A%28m+%2B+3%29\"$
\n" ); document.write( "(2) $\"9+%2B+3+=+%284%2F5%29%2A%2812+%2B+3%29\"$
\n" ); document.write( "(2) $\"12+=+%284%2F5%29%2A15\"$
\n" ); document.write( " $\"12+=+12\"$
\n" ); document.write( "OK
\n" ); document.write( "and, also
\n" ); document.write( "(1) $\"m+=+j+%2B+3\"$
\n" ); document.write( "(1) $\"12+=+9+%2B+3\"$
\n" ); document.write( " $\"12+=+12\"$
\n" ); document.write( "OK \n" ); document.write( "

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