Respuesta :

Step-by-step explanation:

2x + 1 + x - 13 = 180° because these angles are supplementary

3x - 12 = 180°

3x = 180 + 12

3x = 192 divide both sides by 3

x = 64

2x + 1 ➡ 2 × 64 + 1 = 129°

x - 13 ➡ 64 - 13 = 51°