Question 733591
Let their ages be {{{ x }}} and {{{ x + 11 }}}
given:
{{{ x*( x + 11 ) = 210 }}}
{{{ x^2 + 11x - 210 = 0 }}}
I notice that {{{ 210 = 21*10 }}} and {{{ 21 - 10 = 11 }}}
{{{ ( x + 21 )*( x - 10 ) }}}
{{{ x = 10 }}} ( ignore x = -21 )
{{{ x + 11 = 21 }}}
The sum of their ages is {{{ 21 + 10 = 31 }}}