Respuesta :

Answer:

A) 80°

Step-by-step explanation:

55° + 45° + (5x + 30)° = 180°

55° + 45° + 30° + 5x = 180°

130 + 5x = 180°

5x = 50°

x = 10°

=> (5x + 30)° = 5*10° + 30° = 50° + 30° = 80