Answer:
D) Addition property of equality and division property of equality
Explanation:
Step(i):-
Given equation 3 x -6 =12
Apply addition property of equality
Adding '6' on both sides , we get
3 x - 6 + 6 = 12 +6
3 x = 18
Step(ii):-
Apply Division property of equality
Dividing '3' on both sides , we get

on simplification , we get
x = 6
Conclusion:-
The solution of the given equation is x =6