Using the interior angle sum theorem to find x of a quadrilateral

The video tutorial explains how to determine the sum of angles in a quadrilateral, which is 360 degrees. The teacher sets up an equation using the measures of four angles, combines like terms, and solves the equation to find the value of X. The process involves basic algebraic operations and emphasizes the importance of understanding the setup of equations in geometry.

How do you combine like terms in the equation?

What is the final value of X after solving the equation?