Answer:
x=4
Step-by-step explanation:
4x-3=x+9
4x-x-3=9
4x-x=9+3
3x=9+3
3x=12
3/3
12/3=4
X=4
4x-3+3=x+9+3
4x=x+12
4x-x=x+12-x
3x/3=12/3