Respuesta :

Answer:

-3 or 6 I would put -3 but... its your wish

Step-by-step explanation:

Answer:

-3

Step-by-step explanation:

3x + 12 - 2x = 9

Subtract 3x - 2x

x + 12 = 9

subtract 12 to both sides

x = -3

Hope this helps, can you please mark me brainliest? I just need 2 more brainlest to become expert.