1) 2^5 * 2^3 = 2^8 = 256
2) 7^10 : 7^8 = 7^2 = 49
3) 19^1 * 19^7/19^8 = 19^8/19^8 = 1
4) 21^9 : 21^8/21 = 21^1/21 = 1
5) (3^5)^6 : 3^10 = 3^30 : 3^10 = 3^20
6) 3^6 * 3^10 : 3^14 = 3^2 = 9
7) (7^5)^6 : (7^4)^7 = 7^30 - 7^28 = 7^2 = 49
