Answer:
12x + 28 = p
20x + 4 = p
Explanation:
Assuming that both shapes are square, the perimeter of a square is the equation:
4 * x = p
Where x is the length of one side. Plug the variables in for the first square:
4 * (3x + 7) = p
Expand the brackets:
4 * 3x = 12x
4 * 7 = 28
12x + 28 = p
For the second square, plug the variables in again:
4 * (5x + 1) = p
Expand the brackets:
4 * 5x = 20x
4 * 1 = 4
20x + 4 = p
Hope this helps!