Question 1141483
y, man
n, son


{{{system(y-4=(5/2)(n-4),y+5=2(n+5))}}}


{{{system(2y-8=5n-20,y+5=2n+10)}}}


{{{system(2y-5n=-12,y-2n=5)}}}


Multiply the future equation by 5;
Multiply the past equation by 2;



{{{system(4y-10n=-24,5y-10n=25)}}}


{{{E2-E1}}}:
{{{highlight(y=49)}}}