Respuesta :

Answer: a

Step-by-step explanation:

Answer:

D

Step-by-step explanation:

The sum of the 3 angles in a triangle = 180°

Sum the 3 given angles and equate to 180, thus

x + 5 + x + 7x - 5 = 180, that is

9x = 180 ( divide both sides by 9 )

x = 20 → D