Question 557754
{{{P=2l+2w}}}
{{{-2w=2l-P}}}
{{{-2w/-2=(2l-P)-2}}}
{{{cross(-2)w/cross(-2)=(2l-P)/-2}}}
{{{w=(2l-P)/-2}}}
{{{w=2l/-2-P/-2)/-2}}}
{{{w=-l+P/2}}}
{{{w=P/2-l}}}