In this situation, 6 is an even exponent which means that the negative coefficient of this 9th degree monomial will be positive. Now the only step is to multiply the exponents by the exponent outside of the perenthesis which is 6.
so (-a³b⁴c⁹)⁶ = ((-a³)⁶(b⁴)⁶(c⁹)⁶) = ((a³ˣ⁶)(b⁴ˣ⁶)(c⁹ˣ⁶)) = ((a¹⁸)(b²⁴)(c⁵⁴)) = <em>a¹⁸b²⁴c⁵⁴</em>
