I really need help

Simplify the following:
(64/81)^(-2/3)

(64/81)^(-2/3) = (81/64)^(2/3):
(81/64)^(2/3)

(81/64)^(2/3) = (81^(2/3))/(64^(2/3)):
(81^(2/3))/(64^(2/3))

81^(2/3) = (81^2)^(1/3) = (3^8)^(1/3) = 3^2×3^(2/3):
(3^2×3^(2/3))/(64^(2/3))

3^2 = 9:
(9×3^(2/3))/(64^(2/3))

64^(2/3) = (64^2)^(1/3) = (2^12)^(1/3) = 2^4:
(9×3^(2/3))/(2^4)

2^4 = (2^2)^2:
(9×3^(2/3))/((2^2)^2)

2^2 = 4:
(9×3^(2/3))/(4^2)

4^2 = 16:
Answer: |(9×3^(2/3))/(16)

\(\left(\dfrac{64}{81}\right)^{\frac{-2}{3}}\\ = \left(\dfrac{81}{64}\right)^{\frac{2}{3}}\\ =\dfrac{81^{\frac{2}{3}}}{64^{\frac{2}{3}}}\\ =\dfrac{\sqrt[3]{6561}}{\sqrt[3]{4096}}\\ =\dfrac{\sqrt[3]{6561}}{16}\)

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