SOLUTION: the perimeter of a college athletic field is 104 meters and the length is 18 meters more than the width. find the length and width

From the condition, you have these two equations

L + W = ,    (1)
L - W = 18.       (2)

Simplify:

L + W = 52,     (1')
L - W = 18.     (2')

Add (1') and (2'). You will get

2L = 52 + 18 = 70.   Hence,  L =  = 35.

Thus the length of the field is 35 m.

Then from (2) W = L - 18 = 35 - 18 = 17 m.

The width is 17 m.