Question 212194
{{{A=L*W=55}}}
{{{L=W+6}}}
{{{(W+6)W=55}}}
{{{W^2+6W=55}}}
{{{W^2+6W-55=0}}}
{{{(W-5)(W+11)=0}}}
{{{W-5=0}}}
{{{W=5}}}
{{{L=5+6=11}}}
The other solution {{{W+11=0}}} would not make sense here since a negative length is not allowed.