Question 51723
led the width x.
then length will be 2x+8

So rectangle has perimeter which can expressed, 2(a+b), where a-legnth & b-width

So lets  create the equation

     {{{ 2(x+2x+8) = 60 }}}
     {{{3x+8     = 30}}}
     {{{3x    = 22
     {{{x    = 22/3}}}
         {{{ = 7.33334 }}}

So the width is