Question 1063230
w and L
{{{system(2w+2L=90,wL>=250)}}}



{{{w+L=45}}}

{{{L=45-w}}}


Substitute.
{{{wL>=250}}}
{{{w(45-w)>=250}}}
{{{-w^2+45w>=250}}}
{{{-w^2+45w-250>=0}}}
{{{w^2-45w+250<=0}}}
{{{(w-5)(w-50)<=0}}}


Solution is between and including the two zeros.
{{{highlight(5<=w<=50)}}}