Simplify $(7b^3)^2 \cdot (4b^2)^{-3},$ given that $b$ is non-zero.
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<|im_start|>user
Simplify $(7b^3)^2 \cdot (4b^2)^{-3},$ given that $b$ is non-zero.
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<|im_start|>assistant

user
\frac{49}{64}
Simplify $(7b^3)^2 \cdot (4b^2)^{-3},$ given that $b$ is non-zero.
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