Answer
The solutions are $x=-1$ and $x=7$.
Work Step by Step
To solve the given equation graphically, do the following steps:
(1) Use a graphing utility to graph $y=x^2-4x$ (refer to the red graph) and $y=2x+7$ (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 $x=-1$ and $x=7$.
(refer to the attached image below for the graph)