Answer
$(-2,-1)\cup(1,2)$
Work Step by Step
We consider the function:
$f(x)=(x^2-4)(x^2-1)$
Graph the function.
From the graph we determine the solutions of the inequality:
$f(x)<0$,
therefore the values of $x$ for which the graph is under the $x$-axis:
$(-2,-1)\cup(1,2)$
