Answer:
6(x - 3)
Step-by-step explanation:
18(x−3)−6(x−3)2 =>
18x - 54 - 12 (x - 3 ) =>
18x - 54 - 12x + 36 =>
18x - 12x - 54 + 36 =>
6x - 18 or 6(x - 3)
both answers are good, althoguth this second one 6 (x - 3) should be the one that you are looking for