Finding x from Parallel Lines and Angles

In the figure below, line segment AB is parallel to line segment CD. Point E lies on line segment AB and point F lies on line segment CD. If the measure of angle AEF is represented by the expression $(3x + 10)^{\circ}$ and the measure of angle CFD is represented by the expression $(2x + 30)^{\circ}$, what is the value of $x$?

Assuming you have a transversal that intersects both lines AB and CD, both angles AEF and CFD are alternate interior angles. According to the properties of parallel lines, if two parallel lines are cut by a transversal, then the alternate interior angles are equal.

Set up the equation:

$$(3x + 10) = (2x + 30)$$