Question 914747
w and L are width and length.
2w+2L=500 and L=50+3w.



You can do these:
{{{(2w+2L)/2=500/2}}}
{{{w+L=250}}}
;
{{{w+3w+50=250}}}  AND  {{{(L-50)/3+L=250}}} through substitution.