Question 917635
{{{L=3+5W}}}
{{{2L+2W=54}}}
Substituting,
{{{2(3+5W)+2W=54}}}
{{{3+5W+W=27}}}
{{{6W=24}}}
{{{W=4}}}
Then,
{{{L=3+5(4)}}}
{{{L=3+20}}}
{{{L=23}}}