document.write( "Question 959256: can you help me solve the world problem \"Manuel is 8 years older than his sister. Three years ago he was 3 times older than his sister. How old is each now?\" \n" ); document.write( "

Algebra.Com's Answer #586344 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+m+\"$ = Manuel's age now
\n" ); document.write( "Let $\"+s+\"$ = his sister's age now
\n" ); document.write( "------------------------------
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+m+=+s+%2B+8+\"$
\n" ); document.write( "(2) $\"+m+-+3+=+3%2A%28+s+-+3+%29+\"$
\n" ); document.write( "-------------------------
\n" ); document.write( "By substitution:
\n" ); document.write( "(2) $\"+s+%2B+8+-+3+=+3%2A%28+s+-+3+%29+\"$
\n" ); document.write( "(2) $\"+s+%2B+5+=+3s+-+9+\"$
\n" ); document.write( "(2) $\"+2s+=+14+\"$
\n" ); document.write( "(2) $\"+s+=+7+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+m+=+s+%2B+8+\"$
\n" ); document.write( "(1) $\"+m+=+7+%2B+8+\"$
\n" ); document.write( "(1) $\"+m+=+15+\"$
\n" ); document.write( "------------------
\n" ); document.write( "Manuel is 15
\n" ); document.write( "His sister is 7
\n" ); document.write( "-------------
\n" ); document.write( "check:
\n" ); document.write( "Manuel is 8 years older than his sister
\n" ); document.write( "true
\n" ); document.write( "3 years ago he was 12
\n" ); document.write( "3 years ago, his sister was 4
\n" ); document.write( "He was 3 times his sister's age
\n" ); document.write( "true\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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