Hello!
The perimeter of a rectangle is length + length + width + width
We have to make an expression to find this where length is x and width is 4 meters shorter
since the length is x that is
lengths = 2x
The width is 4 meters shorter than x so
widths = 2(x - 4)
Combine these
The answer is 2x + 2(x - 4)
Hope this helps!