Question 630454
{{{ y }}} = Peter's age now
{{{ y - 2 }}} = His brother David's age now
{{{ y + 9 }}} = Peter's age in 9 years
{{{ y - 2 + 9 }}} = David's age in 9 yeats
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given:
{{{ y + 9 + y - 2 + 9 = 2*( y + y - 2 ) }}}
{{{ 2y + 16 = 2*( 2y - 2 ) }}}
{{{ 2y + 16 = 4y - 4 }}}
{{{ 2y = 20 }}}
{{{ y = 10 }}}
{{{ y - 2 = 8 }}}
Peter is 10 now and
David is 8 now