document.write( "Question 921649: john is twice jane’s age. in 2 year’s time, john will be twice as old as jill and she will be twice as old as jane’s age 2 years ago. how old are john, jill and jane? \n" ); document.write( "

Algebra.Com's Answer #559178 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+a+\"$ = John's age now
\n" ); document.write( "Let $\"+b+\"$ = Jill's age now
\n" ); document.write( "Let $\"+c+\"$ = Jane's age now
\n" ); document.write( "---------------------------
\n" ); document.write( "(1) $\"+a+=+2c+\"$
\n" ); document.write( "(2) $\"+a+%2B+2+=+2%2A%28+b+%2B+2+%29+\"$
\n" ); document.write( "(3) $\"+b+%2B+2+=+2%2A%28+c+-+2+%29+\"$
\n" ); document.write( "-------------------------
\n" ); document.write( "(2) $\"+a+%2B+2+=+2b+%2B+4+\"$
\n" ); document.write( "(2) $\"+a+-+2b+=+2+\"$
\n" ); document.write( "and
\n" ); document.write( "(3) $\"+b+%2B+2+=+2c+-+4+\"$
\n" ); document.write( "(3) $\"+-b+%2B+2c+=+6+\"$
\n" ); document.write( "---------------------
\n" ); document.write( "(1) $\"+c+=+%281%2F2%29%2Aa+\"$
\n" ); document.write( "Substitute (1) into (3)
\n" ); document.write( "(3) $\"+-b+%2B+2c+=+6+\"$
\n" ); document.write( "(3) $\"+2%2A%281%2F2%29%2Aa+-+b+=+6+\"$
\n" ); document.write( "(3) $\"+a+-+b+=+6+\"$
\n" ); document.write( "Subtract (2) from (3)
\n" ); document.write( "(3) $\"+a+-+b+=+6+\"$
\n" ); document.write( "(2) $\"+-a+%2B+2b+=+-2+\"$
\n" ); document.write( "---------------------
\n" ); document.write( " $\"+b+=+4+\"$
\n" ); document.write( "and
\n" ); document.write( "(3) $\"+a+-+b+=+6+\"$
\n" ); document.write( "(3) $\"+a+-+4+=+6+\"$
\n" ); document.write( "(3) $\"+a+=+10+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+c+=+%281%2F2%29%2Aa+\"$
\n" ); document.write( "(1) $\"+c+=+5+\"$
\n" ); document.write( "---------------
\n" ); document.write( "John is 10
\n" ); document.write( "Jill is a 4
\n" ); document.write( "Jane is 5
\n" ); document.write( "-----------
\n" ); document.write( "check:
\n" ); document.write( "John is twice Jane's age -OK
\n" ); document.write( "In 2 year’s time, john will be twice as old as jill
\n" ); document.write( "True- John will be 12 and Jill will be 6
\n" ); document.write( "Jill will be twice as old as jane’s age 2 years ago
\n" ); document.write( "True- Jane was 3 and Jill will be 6
\n" ); document.write( "OK\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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