The two angles are vertical angles meaning they are congruent. So we set them equal to each other
3x + 50 = 6x - 10
Now add 10 to both sides
3x + 50 + 10 = 6x - 10 +10
3x + 60 = 6x
Now subtract 3x from both sides
3x + 60 - 3x = 6x - 3x
60 = 3x
Divide by 3 on both sides
60/3 = 3x/3
20 = x
The value of x is 20
Hope this helped!