Question 1071622
x, older person
y, younger person


{{{system(x=3+8y,x+y=30)}}}


{{{(3+8y)+y=30}}}

{{{9y+3=30}}}

{{{3y+1=10}}}

{{{3y=9}}}

{{{highlight(y=3)}}}
-
{{{highlight(x=27)}}}