First one: -1/9
Distribute the exponent to the 1 and 3, which becomes 1/9 (because 3^2 is 3*3), then add the negative sign at the end, and you get the answer.
Second one: 8/3
2 to the 3rd power is 2*2*2 which is 8, and you can’t simplify 8/3 more into a rational number.