Answer:
34
Step-by-step explanation:
The coordinates are (6,-9) (-12,-3) (0,-7)
you put 6 in the place of x to get 6+3y=-21 then you must take 6 away from each side to get 3y= -27 then divide each side by 3 so -27 divided by 3 is -9. do this for all of them! hope it helped!
I think the answer will be B
