The length of a rectangular box is 2 units less than its width.
if the area of the box is 15 units square.
find the perimeter of the box.

 ' L ' be Length , ' W ' be Width , ' P ' be perimeter and ' A ' be the area of the rectangular box. 

L = W − 2 
A = LW 
15 = (W)(W − 2) 
W² − 2W − 15 = 0 
W² − 5W + 3W − 15 = 0 
W(W − 5) + 3(W − 5) = 0 
(W + 3)(W − 5) = 0 
W = + 5 , − 3 

Negative lengths r stupid soo 
[ W = 5 linear units ] 

L = W − 2 
L = 5 − 2 
[ L = 3 linear units ] 

P = 2(L + W) 
P = 2(3 + 5) 
[ P = 16 linear units ] 

Happy studying ^_^