Please check my answers! Thank you!

Question

Simplify the following expressions. Collapse “x” terms, and/or simplify fractions and exponents.
1.) (12/5) / (36/20) = 4/3
2.) x^13*x^3 = x^16
3.) x^4 / (x^2)^3 = 1/x^2
4.) x^-3 / x^2 = x^-5
5.) (x^2-8x+16) / (x-4) = x-4
6.) x^(-1/3) / x^(3/4) = 1/ x^(13/12)
7.) x^(1/3) / x^(-2/3) = x
8.) (3/9(4*x -3)^(-3/4) y^(6/7)) /
(5/18(4*x -3)^(1/4) y^(1/7))
= (6y^(5/7)) / 5(4x-3)

Answer 1

1. 12/5 * 20/30=2*4/10=4/5
others look right

Answer 2

(3x^ay^bz^c) (-y^fz^g)