Solve for brainless!

Answer:
15. 1/3 times 1/3 times 1/3 times 1/3 and 1/81
16. 3/4 times 3/4 and 9/16
17. 2 to the 5th power
18. 4 to th2 4th power
19. 2 to the 4th power, 5 to the 2nd power, and 3 to the 3rd power
Step-by-step explanation:
Hope this helps