Answer
(a) $x=10$
(b) $x=5$
Work Step by Step
(a)
We are given:
$\log_{x}1000=3$
This means:
$ x^{3}=1000$
$ x=(1000)^{1/3}=10$
(b)
We are given:
$\log_{x}25=2$
This means:
$x^{2}=25$
$x=\pm\sqrt{25}=\pm 5$
$x=5$
(a log base can't be negative)