Answer: 7
Step-by-step explanation:
-if y is the width and the length of area k (see diagram), the difference between n and y is of 2 square sides, one at each side of y.
-therefore, assuming that n is a whole number and that there aren’t half squares, y must be a whole number too because, as previously said, n-y = 2 so y= n -2
-the only perfect square amongst the values for k you listed is 25, so taking n and y as whole numbers the only possible value for k is 25
-therefore y is 5 and n is 7 because n-y = 2 so y + 2 = n
