Answer:
x = 6
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
Sum the 3 angles and equate to 180
13x - 5 + 67 + 40 = 180
13x + 102 = 180 ( subtract 102 from both sides )
13x = 78 ( divide both sides by 13 )
