Question 1202194
w, width
2w+1, length
w(2w+1)=45 for area


Not the only way to solve but
{{{2w^2+w-45=0}}}
-
discriminant, {{{1+4*2*45=361=19^2}}}


{{{w=(-1+19)/4}}}

{{{highlight(w)=18/4=9/2=highlight(4&1/2)}}}