Answer:
x = 11.428
Explanation:
See the diagram of angles attached to this question.
XY is a segment of straight line and straight line n is a transverse and they meet at point M.
So, the angles formed by the transverse line will be supplementary.
Therefore, from the diagram, (5x + 8) + (9x + 12) = 180°
⇒ 14x + 20 = 180
⇒ 14x = 160
⇒ x = 11.428 (Answer)