Answer:
1/a^8/5 for the first, 9b^8/3 for the second, and 8x^25/7 for the third
Explanation:
1) With neg exponents, you can just take it and flip it, and make the exp pos i.e. 1/a^8/5
2) When there is an exponent outside of parenthesis of a number with an exponent, you multiply the exponents together i.e. 9b^8/3
3) The same applies to this as the 2nd, we just multiply to get 8x^25/7