Question 1074124
Original Rectangle

Dimensions w and 3w-2

Perimeter p,
{{{p=2(3w-2)+2w}}}





New Rectangle

Dimensions 3w and 3w-2-2=3w-4

Perimeter description,
{{{34+p/2=2(3w-4)+2*3w}}}



Simplify the two equations.  
Solve the two equations as a system for w and evaluate length.
(perimeter p can also be solved for.)