Question 1021952
{{{A=L*W=21}}}
{{{W=L/2-1/2}}}
Substituting,
{{{L(L/2-1/2)=21}}}
{{{L(L-1)=42}}}
{{{L^2-L-42=0}}}
{{{(L-7)(L+6)=0}}}
Only the positive L makes sense in this problem.
{{{L-7=0}}}
{{{L=7}}}{{{m}}}
Then,
{{{W=7/2-1/2}}}
{{{W=6/2}}}
{{{W=3}}}{{{m}}}