document.write( "Question 1040471: John's father is 26 years younger than John's grandfather and 29 years older than John. The sum of all the three is 135 years . What is the age of each one of them ? \n" ); document.write( "

Algebra.Com's Answer #655284 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+a+\"$ = John's age now
\n" ); document.write( "Let $\"+b+\"$ = John's father's age now
\n" ); document.write( "Let $\"+c+\"$ = John's grandfather's age now
\n" ); document.write( "------------------------------------
\n" ); document.write( "(1) $\"+b+=+c+-+26+\"$
\n" ); document.write( "(2) $\"+b+=+a+%2B+29+\"$
\n" ); document.write( "(3) $\"+a+%2B+b+%2B+c+=+135+\"$
\n" ); document.write( "----------------------
\n" ); document.write( "There are 3 equations and 3 unknowns, so it's solvable
\n" ); document.write( "(1) $\"+c+=+b+%2B+26+\"$
\n" ); document.write( "(2) $\"+a+=+b+-+29+\"$
\n" ); document.write( "Substitute (1) and (2) into (3)
\n" ); document.write( "(3) $\"+b+-+29+%2B+b+%2B+b+%2B+26+=+135+\"$
\n" ); document.write( "(3) $\"+3b+=+135+%2B+29+-+26+\"$
\n" ); document.write( "(3) $\"+3b+=+138+\"$
\n" ); document.write( "(3) $\"+b+=+46+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+a+=+b+-+29+\"$
\n" ); document.write( "(2) $\"+a+=+46+-+29+\"$
\n" ); document.write( "(2) $\"+a+=+17+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+c+=+b+%2B+26+\"$
\n" ); document.write( "(1) $\"+c+=+46+%2B+26+\"$
\n" ); document.write( "(1) $\"+c+=+72+\"$
\n" ); document.write( "---------------------
\n" ); document.write( "John's age is 17
\n" ); document.write( "John's father's age is 46
\n" ); document.write( "John's grandfather's age is 72
\n" ); document.write( "---------------------------
\n" ); document.write( "check:
\n" ); document.write( "(3) $\"+a+%2B+b+%2B+c+=+135+\"$
\n" ); document.write( "(3) $\"+17+%2B+46+%2B+72+=+135+\"$
\n" ); document.write( "(3) $\"+135+=+135+\"$
\n" ); document.write( "OK \n" ); document.write( "

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