P = 2L + 2W, keep that in mind (W=width, L=length)
Just fill it in. 82=2(5+2w) + 2w. First solve for w.
82 = 10+ 10w + 2w,
82 = 10 + 12w. Now subtract the 10 from both sides, and get:
72 = 12w, now divide both sides by 12, and get:
6 = w.
W is 6.
Now to solve for L, go back to the problem we had, L = 5 + 2w. Fill in w,
L = 5 + 2(6), and then it is L = 5 + 12.
It is a simple addition equation now.
L = 17, W = 6
