Rules of indices are as follows :
1) a^m X a^n = a^(m+n) for example 2^3 X 2^5 = 2^8
2) a^m / a^n = a^(m-n) for example 2^5 / 2^3 = 2^2
3) a^m = 1 / a^(-m) or a^(-m) = 1/a^m For example 9^(-6)=1/9^6
4) (a^b)^c = a^(bc) thus (3^3)^2 = 3^6
5) a^0 = 1 for all the values of a. Thus 7^0 = 1
6) If a^m = n, then a= n^(1/m)
7) (a^n)/(b^n) = (a/b)^n