The given equation is: P = 2w + 2l We are given that: P = 38 l = 12
Substitute with these two givens in the above equation to get the value of w which is the only unknown as follows: P = 2w + 2l 38 = 2w + 2(12) 38 = 2w + 24 38 - 24 = 2w 2w = 14 w = 14/2 = 7