(4x^6)(-3x^9)(6x^7)

(4x^6)(-3x^9)(6x^7)

4 x -3 x 6 = -72
x^6 * x^9 * x^7 = x^22 (add the exponents)

(4x^6)(-3x^9)(6x^7) = -72x^22