Relax

Respuesta :

Answer:

[tex]B. x=21[/tex]

Step-by-step explanation:

[tex]x- 12 = 9 \\ x = 12 + 9 \\ x = 21[/tex]

B.
You add +12 to both sides and the left side cancels out, leaving X. Then 9+12=21. So X=21