Respuesta :

Answer:

67°.

Step-by-step explanation:

1) m∠PMR=m∠LMN=3x+19°;

2) m∠LMN+m∠LMP=180°, it can be written as 3x+19+9x-31=180;

3) if to solve the equation 3x+19+9x-31=180, then x=16;

4) m∠PMR=3x+19=48+19=67°.