Since a square has 4 equal sides, we can write an eqauation like this:
3x = 5x - 8
Steps to solve:
3x = 5x - 8
~Subtract 5x to both sides
-2x = -8
~Divide -2 to both sides
x = 4
Therefore, each side length is 4 units.
Perimeter formula: 2w + 2l = p
2(4) + 2(4) = p
8 + 8 = p
16 = p
Therefore, the perimeter is equal to 16 units.
Best of Luck!