Which statement shows the associative property of addition?

(A)21 + 2y = 2y + 21

(B)(u + 7) + 13 = u + (7 + 13) .
(C)If m + 3 = 18, then 18 = m + 3.

(D)3⋅(5⋅x)=(3⋅5)⋅x

7 answers

Associative property of addition tells us :

a + b + c
= (a + b) + c = a + (b + c)

do you see that pattern?
I think it is A
Or B?
Are you just guessing????

compare:

(u + 7) + 13 = u + (7 + 13)
(a + b) + c = a + (b + c)
No, I am not guessing.
Ya B???
(×+7)+1= associaltive property