Which statement shows the associative property of addition?
A.
If m + 3 = 18, then 18 = m + 3
B.
(u + 7) + 13 = u + (7 + 13)
C.
21 + 2y = 2y + 21
D.
3 · (5 · x) = (3 · 5) · x
A.
If m + 3 = 18, then 18 = m + 3
B.
(u + 7) + 13 = u + (7 + 13)
C.
21 + 2y = 2y + 21
D.
3 · (5 · x) = (3 · 5) · x
