Answer:
x = 22
Step-by-step explanation:
The 3 angles in a triangle sum to 180°
The third angle in the triangle forms a straight angle with 6x + 1
⇒ third angle = 180° - (6x + 1)° = 180 - 6x - 1 = 179 - 6x
Summing the 3 angles and equating to 180
179 - 6x + 79 + 2x + 10 = 180
- 4x + 268 = 180 ( subtract 268 from both sides )
- 4x = - 88 ( divide both sides by - 4 )
x = 22