Question 1114832
y, father's current age


{{{x+2x+3x=y}}}
{{{6x=y}}}



Eight years later or now, same difference of age between youngest son and father.  Same 35 year difference.


{{{y-x=35}}}



You can solve the system,  {{{system(6x=y,y-x=35)}}}.

Eldest son is {{{3x}}}.


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{{{6x-x=35}}}
{{{5x=35}}}
{{{highlight(x=7)}}}-------youngest son
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{{{highlight(21)}}}--------oldest son