Answer:
x = 5
Step-by-step explanation:
The sum of the angles of a triangle is 180°.
(180 - 18x + 5) + (-1 + 8x) + 46 = 180
⇒ 180 - 18x + 5 - 1 + 8x + 46 = 180
⇒ -10x + 230 = 180
⇒ -10x = -50
⇒ x = 5
