Question

ecuación de 7b + 21 = 8b - 12​

Answer 1

7b + 21 = 8b - 12​

12​ + 21 = 8b - 7b

33 = b

Answer 2

Respuesta:

7b+21=8b-12

21-12=8b-7b

9=1b

9/1=b

b=9