Question 928959

since the width of the border is {{{x}}}, solve

{{{2(8-2x)+2(4-2x)=18}}} for {{{x}}}

{{{cross(2)(8-2x)+cross(2)(4-2x)=cross(18)9}}}

{{{8-2x+4-2x=9}}}

{{{12-4x=9}}}

{{{12-9=4x}}}

{{{3=4x}}}

{{{3/4=x}}}

so, the width of the border is {{{3/4}}}