Question 606564
let {{{ a + b + c + d = 46 }}} five years ago
Now each person is five years older, so
{{{ a + 5 + b + 5 + c + 5 + d + 5 = a + b + c + d + 20 }}}
{{{ a +_ b + c + d + 20 = 46 + 20 }}}
{{{ 46 + 20 = 66 }}}
The sum of their ages now  is 66