Question 1023653
Let {{{ h }}} = Harry's age now
{{{ h + 3 = 2*( h - 6 ) }}}
{{{ h + 3 = 2h - 12 }}}
{{{ h = 15 }}}
Harry is 15 now
In 3 yrs:
{{{ h + 3 = 15 + 3 }}}
{{{ h + 3  = 18 }}}
Harry will be 18
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Six years ago:
{{{ h - 6 = 15 - 6 }}}
{{{ h - 6 = 9 }}}
Harry was 9