Question 991022
L and w;
{{{L=w+4}}}
and
{{{wL=71}}}


{{{w(w+4)=71}}}
{{{w^2+4w-71=0}}}


{{{w=(-4+sqrt(4^2-4(-71)))/2}}}
{{{w=(-4+2sqrt(1+71))/2}}}
{{{w=-2+sqrt(72)}}}
{{{highlight(w=-2+6sqrt(2))}}} and you can evaluate L.