This paper establishes three formulas for solving three special classes of congruences of prime moduli of higher degree. The formulas are tested using examples. The first formula reduces a congruence of the form x ≡ a (mod p) to a biquadratic congruence that can be easily solved. The second and third formulas show that congruences of the forms x ≡ a*b (mod p) and x ≡ a^b (mod p) each have a unique solution given by x ≡ a*b (mod p) and x ≡ a^b (mod p), respectively. Examples are provided to verify the formulas. The paper concludes that the formulations make solving these congruences