Thevenin Equivalent Circuit & Superposition Example Problem

This is similar to problem 3.65 in "Circuit Analysis and Design" by Ulaby, Maharbiz, and Furse. This is a free/open educational textbook on basic circuit design found here: https://cad.eecs.umich.edu/ We will create a Thevenin equivalent circuit and use superposition to solve for the voltage at the circuit terminals.