Express each expression using a positive exponent. 1.8 ିହ2. 3 ିଽ3. ݖ ିଶ4. ݌ ିସ

1. $\frac{1}{8^2}$

2. $\frac{1}{3^3}$

3. $\frac{1}{7^4}$

4. $\frac{1}{6^5}$