Question 987861
Let {{{ j }}} = Julie's age now
Let {{{ s }}} = sister's age now
--------------------------
{{{ j = 2*( s - 6 ) - 3 }}}
{{{ j = 2s - 12 - 3 }}}
{{{ 2s = j + 15 }}}
{{{ s = (1/2)*j + 7.5 }}}
The sister is 7.5 yrs older than 1/2 Julie's age now