Step-by-step explanation:
[tex] = {3}^{0} \times {3}^{ - 3} [/tex]
[tex] = 1 \times \frac{1}{ {3}^{3} } [/tex]
[tex] = \frac{1}{3 \times 3 \times 3} [/tex]
[tex] = \frac{1}{27} [/tex]