Question 1141112
The description seems unrealistic.


4x, Father
x, Son
In ten years, x=0, not realistic


{{{x+10=0}}}
{{{x=-10}}}
-
{{{4x=-40}}}
-


No sensible meaning.  Father would be at any time, of less age than son, which is nonsense.  {{{-40<-10}}}.


Nonsense.