#### Answer

$x=\left\{-2.724, -1.15, 1, 2.874\leq\right\}$
Refer to the image below for the graph

#### Work Step by Step

To solve the given equation graphically, perform the following steps:
(1) Let each side of the equation represent a function then graph each function on the same coordinate plane.
Graph $y=x^4-9x^2$ (the blue graph) and $y=x-9$ (the red graph).
(refer to the attached image in the answer part above for the graph)
(2) Identify the point/s where the two graphs intersect. The x-coordinate of point of intersection is a solution of the given equation.
The graphs intersect at $(-2.724,-11.724)$, $(-1.15,-10.15)$, $(1, -8)$, and $(2.874,-6.126)$.
Therefore, the solutions to the given equation are:
$x=\left\{-2.724, -1.15, 1, 2.874\leq\right\}$