46 / 2 = 23, so 3x - 1 = 23.
3x - 1 = 23
= 3x - 1 + 1 = 23 + 1
= 3x = 24
= 3x / 3 = 24 / 3
= x = 8
So now that we know the length of the rectangle, 8 cm, all we have to do is do 2(8) + 2(2).
2(8) + 2(2) = 20.
The perimeter is 20 square cm.
Hope this helps! Have a great day :)