Solving for x in Vertical Angles

In a geometric configuration, two intersecting lines create pairs of angles. Suppose lines $l$ and $m$ intersect, forming angles labeled as follows:

Angle 1 is formed by ray $OA$ and ray $OB$. Angle 2 is formed by ray $OC$ and ray $OB$. If angle 1 measures $3x + 15^{ ext{o}}$ and angle 2 measures $5x - 5^{ ext{o}}$, and it is given that these angles are vertical angles, what is the value of $x$?