To calculate \( 9^{-7} \), you can use the property of exponents that states \( a^{-n} = \frac{1}{a^n} \).
Thus,
\[ 9^{-7} = \frac{1}{9^7} \]
Now, \( 9^7 \) can be calculated as:
\[ 9^7 = (3^2)^7 = 3^{14} \]
To find the numerical value, we can calculate \( 9^7 \):
\[ 9^7 = 4782969 \]
Therefore,
\[ 9^{-7} = \frac{1}{4782969} \approx 2.093 \times 10^{-7} \]
So, \( 9^{-7} \) is approximately equal to \( 2.093 \times 10^{-7} \).