Question 7183
The formula for a rectangle is P=2(length+width)
W=x
L=2+w

52=2(w+w+2)

52=2w+2w+4 Subtract 4 from both sides and add the 2w + 2w
48=4W
12=W
Width = 12
Length = 14
Check you answer 

p=2(12+14)
P=24+28
Perimeter is 52

I hope that helps you.