Question 174027
The width is {{{w}}} so the length is {{{3w}}}.  The area of the original rectangle is then {{{3w^2}}}


The smaller rectangle measures {{{w-2}}} by {{{3w-2}}}, and the new area is {{{3w^2-8w-4}}}, but this new area is {{{36cm^2}}} smaller than the original, so


{{{3w^2-8w-4=3w^2-36}}}


Collect terms, solve for {{{w}}} and you have the original width.