Answer:
3x
Step-by-step explanation:
A rectangle is similar to a square, in the sense that opposite sides will always be the same. Because we are given the side of the length is 3x-3, this means that the other length will too be 3x-3. Now, we may add these:
(3x-3)+(3x-3)=6x-6
And because we are given our perimiter, simply subtract the lengths we do know:
(12x+6)-(6x-6)=6x
This is the perimetor we have left in our shape. Because we again know that opposing sides are the same length, simply dividing our answer by two will give us the length we need:
6x/2=3x
Based on this, our length of the indicated side is 3x!
Hope this helped!
