Question

Simplify (2a^-3b^2)^3 6b^6/ a9 8b^6/ a^9 6b^5 8b

Answer 1

I'm going to assume that you accidentally missed a set of parentheses and that the expression is $(2a^{-3} b^{2})^3$
Raise 2, $a^{-3}$, and $b^2$ to the third power:
$2^3(a^{-3})^3(b^2)^3$
When a variable raised to a power is raised to another power, the exponents are multiplied:
$8a^{-9}b^{6}$
Negative powers are the positive power in the denominator:
$\frac{8b^6}{a^{9}}$
Therefore, the answer is the second option.

Answer 2

$(2a^{-3}b^2)^3 \\ \\ = 2a^{-9}b^6 \\ \\ = { \frac{b^6}{2a^9} }$
$If\ your\ question\ mean\ (2a^{-3}12b^2)^3 \\ \\ \\ \\ (2a^{-3}12b^2)^3 \\ \\ =2a^{-9}12b^6 \\ \\ ={ \frac{12b^6}{2a^9} } \\ \\ ={ \frac{6b^6}{a^9} }$