First simplify 3x + 12 - 6x to -3x - 12
Next subtract 12 from both sides
Next subtract -9 - 12 and that would be -21
Next divide both sides by -3
Next lets simplify the fraction -21/-3 into 21/3 since those two negatives make a positive.
Lastly simplify the fraction 21/3 to get the answer.
Answer: x ≥ 7