Question 329264
1.{{{L=6+S}}}
2.{{{J=5+L}}}
3.{{{L+J+S=41}}}
From eq. 1, 
{{{S=L-6}}}
Substitute this result and eq. 2 into eq. 3,
{{{L+5+L+L-6=41}}}
{{{3L=42}}}
{{{L=14}}}
{{{S=14-6=8}}}
Sue is 8 years old.