Answer: C. division property of =
Step-by-step explanation:
All you simply did was divide the terms on each side by 4.
So, 4x = 12 becomes (4÷4)x = 12÷4, which is what was done on line 5.
The division property is when both sides of an equation are divided by the same number.
Bonus:
Line 8- D. multiplication of real numbers
Line 3- B. substitution property of =
Line 2- D. segment addition postulate
I hope this helped!
Good luck <3