Answer:
3^18
Step-by-step explanation:
[tex](3^6)^3\\\\\mathrm{Apply\:exponent\:rule}:\quad \left(a^b\right)^c=a^{bc},\:\quad \:a\ge 0\\\left(3^6\right)^3=3^{6\times\:3}\\\\=3^{6\times\:3}\\\\=3^{18}\\\\=387420489[/tex]
