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°.

Find x

Linear pairs are supplementary

  • 9x-31+3x+19=180
  • 12x-12=180
  • x-1=15
  • x=15+1=16

So

opposite angles are equal

  • m=9(16)-31=144-31=113°