Answer
The solutions are:
$x=-1$
$x=-1.15$
$x \approx -2.724$
$x \approx 2.874$
Work Step by Step
To solve the given equation graphically, do the following steps:
(1) Use a graphing utility to graph $y=x^4-9x^2$ (refer to the red graph) and $y=x-9$ (refer to the blue graph);
(2) Identify the points where the graphs intersect each other. The x-coordinates of these points are the solutions to the given equation.
Thus, the solutions are:
$x=-1$
$x=-1.15$
$x \approx -2.724$
$x \approx 2.874$
(refer to the attached image below for the graph)