## College Algebra (10th Edition)

$x=-4$
Note that $16=2^4$. Thus, the given equation is equivalent to: $2^{-x} = 2^4$ Use the rule $a^m=a^n \longrightarrow m = n$ to obtain: $2^{-x}=2^{4} \longrightarrow -x = 4 \longrightarrow x=-4$