What property is shown by the equation?
column a column b
1.
–(–33 + 18) = 33 + (–18)
2.
–10 + (–15) = –15 + (–10)
3.
4 + (29 + 16) = 4 + (16 + 29)
4.
–12 + (12 + 27) = (–12 + 12) + 27
a.
commutative property
b.
associative property
c.
opposite of a sum property