## College Algebra (10th Edition)

$x=-2$
Write $25$ as $5^2$ to obtain: $5^{-x} = 5^2$ Use the rule $a^m=a^n\longrightarrow m=n$ to obtain: $-x=2 \\-1(-x)=-1(2) \\x=-2$ Thus, the solution is $x=-2$.