Answer:
D
Explanation:
3x+9+6=6
step 1 combine like terms
9+6=15
now we have
3x+15=6
step 2 subtract each side by 15
15-15 cancels out
6-15=-9
now we have
3x=-9
step 3 divide each side by 3
3/3 cancels out
-9/3=-3
x=-3
The reason it can also be -3 is because I I means absolute value and the absolute value of negative 3 is positive 3
Have a great day :D