What is the value of x? Enter your answer in the box. x = [ ]

Since both angles are vertical angles, we need to set them equal to each other.
[tex]2(x + 10) = 3x - 30\\\\2x + 20 = 3x - 30\\\\5x + 20 = 30\\\\5x = 50\\\\x = 10[/tex]
The final answer is x = 10.