Respuesta :

3)
Perimeter of square = 4a
P = 4a
so
a = P/4
a = (12x^5 - 8x^2 + 20x - 4)/ 4
a = 3x^5 - 2x^2 + 5x - 1

answer
side = 3x^5 - 2x^2 + 5x - 1