Question

What is the value of x is?

Answer 1

The applicable theorem is the one that tells you the exterior angle is equal to the sum of the opposite interior angles.
  9x = (5x) +(9 +x)
  9x = 6x +9 . . . . . . . . collect terms
  3x = 9 . . . . . . . . . . . . subtract 6x
  x = 3 . . . . . . . . . . . . . divide by 3

The value of x is 3.

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The angles (clockwise from left) are then
  (9*3)° = 27°
  (5*3)° = 15°
  (9 +3)° = 12°
This is an obtuse triangle, obviously not drawn to scale.