Since this is a polygon with 6 sides, it has a total of 720 degrees.
So adding together all the angles, you get:
(2x-50) + (x+40) + (x+20) + x + 150 + 80.
Simplify.
5x+240. And since you know all the angles add up to 720 degrees, set it equal to each other.
5x+240 = 720
5x= 480 (720-240)
x= 96
Finally, plug in x to get the rest of your answers.