Answer:
the commutative property of addition :)
Hey!
------------------------------------------------
Steps To Solve:
~Subtract n to both sides
3 - n = n + 4 - n
~Simplify
3 - n = 4
~Subtract 3 to both sides
3 - n - 3 = 3 - 4
~Simplify
n = -1
------------------------------------------------
Answer:

------------------------------------------------
Hope This Helped! Good Luck!
Answer:
the answer is a
Step-by-step explanation:
14n + 21
Just distribute the 7 to the 2n and the 3.
7(2n + 3)
(7 * 2n) + (7 * 3)
14n + 21
Please consider marking this answer as Brainliest to help me advance.