What is an algebraic expression to find the number of squares in the border of a 75x75 grid?

Well, if the grip is 75 x 75, you can rule out that the grid is 75 squares in each border.

Step-by-step explanation:

75 x 75 = a x b

a = horizontal side lengths

b = vertical side lengths

Rule that a = 75 squares and b = 75 squares.