What is the value of x

x = 20°
The total sum of interior angles in a triangle is 180°
Answer:
D) x = 20
Step-by-step explanation:
Theorem
The sum of the interior angles of a triangle is 180°
Solution
Add the angles and equate to 180:
⇒ (x + 5) + (7x - 5) + x = 180
Collect like terms:
⇒ x + 7x + x + 5 - 5 = 180
Combine like terms:
⇒ 9x = 180
Divide both sides by 9:
⇒ x = 20