<PRE><B>Question 38463</B>
The formula for perimeter is P = 2L + 2W
Let W be the width.
The length L is given in the problem as W - 5.
Now substitute
56 = 2(W - 5) + 2W
56 = 2W - 10 + 2W
56 = 4W - 10
66 = 4W
W = 66/4 = 33/2 = 16 1/2
L = W - 5 = 11 1/2</PRE>