Question 979145
Your question is changed slightly.  Assumption is that your second sentence stays for the past tense.


y, father
x, son


{{{system(x+y=52,y-3=2+3*(x-3))}}}



Simplifying the past equation,
{{{y-3=2+3x-9}}}
{{{y=3x+2-9+3}}}
{{{y=3x-4}}}
-
{{{x+y=52}}}
{{{x+3x-4=52}}}
{{{4x=52+4}}}
{{{x=13+1}}}
{{{highlight(x=14)}}}
-
{{{x+y=52}}}
{{{y=52-x}}}
{{{y=52-14}}}
{{{highlight(y=38)}}}