document.write( "Question 612339: Jenny is 5 years older than her brother. 4 years ago the product of their ages was the same as 37 more than Jenny's present age subtracted from the square of the brother's present age. \n" ); document.write( "

Algebra.Com's Answer #385357 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+j+\"$ = Jenny's age now
\n" ); document.write( "Let $\"+b+\"$ = Brother's age now
\n" ); document.write( "Given:
\n" ); document.write( "(1) $\"+j+=+b+%2B+5+\"$
\n" ); document.write( "(2) $\"+%28+j+-+4+%29%2A%28+b+-+4+%29+=+b%5E2+-+%28+j+%2B+37+%29+\"$
\n" ); document.write( "(2) $\"+j%2Ab+-+4b+-+4j+%2B+16+=+b%5E2+-+j+-+37+\"$
\n" ); document.write( "(2) $\"+j%2Ab+-+4b+%2B+16+=+b%5E2+%2B+3j+-+37+\"$
\n" ); document.write( "(2) $\"+j%2Ab+%2B+16+=+b%5E2+%2B+4b+%2B+3j+-+37+\"$
\n" ); document.write( "(2) $\"+j%2Ab+%2B+53+=+b%5E2+%2B+4b+%2B+3j+\"$
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+%28+b+%2B+5+%29%2Ab+%2B+53+=+b%5E2+%2B+4b+%2B+3%2A%28+b+%2B+5+%29+\"$
\n" ); document.write( "(2) $\"+b%5E2+%2B+5b+%2B+53+=+b%5E2+%2B+4b+%2B+3b+%2B+15+\"$
\n" ); document.write( "(2) $\"+7b+-+5b+=+53+-+15+\"$
\n" ); document.write( "(2) $\"+2b+=+38+\"$
\n" ); document.write( "(2) $\"+b+=+19+\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+j+=+b+%2B+5+\"$
\n" ); document.write( "(1) $\"+j+=+19+%2B+5+\"$
\n" ); document.write( "(1) $\"+j+=+24+\"$
\n" ); document.write( "Jenny is 24 and her Brother is 19
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+%28+j+-+4+%29%2A%28+b+-+4+%29+=+b%5E2+-+%28+j+%2B+37+%29+\"$
\n" ); document.write( "(2) $\"+%28+24+-+4+%29%2A%28+19+-+4+%29+=+19%5E2+-+%28+24+%2B+37+%29+\"$
\n" ); document.write( "(2) $\"+20%2A15+=+361+-+61+\"$
\n" ); document.write( "(2) $\"+300+=+300+\"$
\n" ); document.write( "OK\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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