Respuesta :

-12=3x+3
Subtract 3 from each side
-15=3x
Divide both sides by 3
-5=x
-12 = 3x + 3

-12 - 3 = 3x    subtract both sides by 3

-15 = 3x        

-15/3 = x     divide both sides by 3

-5 = x

hope this helps, God bless!