Answer:
13. 5^-9
14. -7^-36
15. (1/4)^2 or 1/16
16. (117/25)^-4
Explanation:
Question 13:
5^13/5^22 = 5^13-22
= 5^-9
Question 14:
(-7^12)^-3 = -7^12(-3)
= -7^-36
Question 15:
(1/4)^-3 x (1/4)^5 = (1/4)^(-3)+(5)
= (1/4)^2
= 1/16
Question 16:
2.6^-8 x 1.8^-4 = 4.68^-4
= (117/25)^-4