Respuesta :

norsch24

Answer:

a = 29

b = 20

Step-by-step explanation:

2a - 1 = 57

    + 1     + 1

2a = 58

/ 2    / 2

a = 29

2a - 1 + 7b - 17 = 180

2 (29) - 1 + 7b - 17 = 180

58 - 1 + 7b - 17 = 180

57 + 7b - 17 = 180

7b + 40 = 180

      - 40     - 40

7b = 140

/ 7      / 7

b = 20