#### Answer

$-3$

#### Work Step by Step

$\left( \dfrac {1}{4}\right) ^{x}=4^{-x}=64=4^{3}\Rightarrow -x=3\Rightarrow x=-3$

Published by
Pearson

ISBN 10:
013421742X

ISBN 13:
978-0-13421-742-0

$-3$

$\left( \dfrac {1}{4}\right) ^{x}=4^{-x}=64=4^{3}\Rightarrow -x=3\Rightarrow x=-3$

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