The answer is Commutative Property.
If you do not mind me asking, what did Seth write? Us helpers cannot answer it if we do not have the full question. I apologize if this seems rude.
Answer:
x = -11
Step-by-step explanation:
2x + 23 + 9 = x + 21
Combine common factors
2x + 32 = x + 21
Subtract x from both sides
x + 32 = 21
Subtract 32 from both sides
x = -11
Answer:
52.5
Step-by-step explanation: