Answer
$ a.\quad$ unhealthy.
$ b.\quad$not unhealthy.
Work Step by Step
a.
Does $x=97$ satisfy
$|x-98.6|\geq 1.5\quad ?$
$|97.0-98.6|=|-1.6|=1.6$
Since $1.6\geq 1.5$, the temperature $97^{o}F$ is unhealthy.
b.
Does $x=100$ satisfy
$|x-98.6|\geq 1.5\quad ?$
$|100.0-98.6|=|1.4|=1.4$
Since $1.4\lt 1.5$, the temperature $100^{o}F$ is not unhealthy.
