Which of the following equations could you solve by first adding six and then dividing by negative three? 6 - 3 x = -9
+ 6 = -9
-3 x - 6 = -9
3 x - 6 = -9

-3x - 6 = -9    (The third answer)

Step-by-step explanation:

When solving for x, you have to undo each operation. When solving -3x - 6 = -9, you have to undo the -6 first. To do this, add 6 to both sides. Then, you must undo the -3x. To do this, divide by -3 from both sides.