Step-by-step explanation:
Fractions with only factors of 2 and 5 are terminating. If not, they give repeating decimals.
Therefore 17/8 and 34/16 are terminating whereas 2/13, 5/24 and 6/7 are repeating decimals.
Answer: 729
Step-by-step explanation:

3^-2 = 1/9
3^-4 = 1/81
(-1)^2 = 1
1/(1/9 * 1/81 * 1)
1/ 1/729 = 729
Answer to Problem 1: 5√3
Answer to Problem 2: 21√5
Answer: 
<u>Step-by-step explanation:</u>
Note the following identities: tan² x = sec²x - 1

tan² x + sec x = 1
(sec² x -1) + sec x = 1
sec² x + sec x - 2 = 0
(sec x + 2)(sec x - 1) = 0
sec x + 2 = 0 sec x - 1 = 0
sec x = -2 sec x = 1

-(-2)^4 = 16
The - sign multiplies inside the bracket to a positive, 2^4 = 16