please help MEEEEEEEE I WILL MARK YOU BRAINLIEST

Answer:
x = 9
Step-by-step explanation:
move the 3 to the 12 and change it from pos to neg so 12-3=9
Answer:
x = 9
Step-by-step explanation:
move the 3 to the 12 and change it from pos to neg so 12-3=9