Answer:
factor the polynomial
9x^4 + 12x^3 + 6x = 3x(3x^3 + 4x^2 + 2)
the coefficients have no common factors other than 1.
the GCD of 9x^4 + 12x^3 + 6x is simply the lowest common factor raised to the power of 1, which is x:
PGCD(9x^4 + 12x^3 + 6x) = x
Explanation: