which pair of expressions is equivalent using the associative property of multiplication?
5(3a ⋅ 4) = 15a ⋅ 20
5(3a ⋅ 4) = (3a ⋅ 4) ⋅ 5
5(3a ⋅ 4) = (5 ⋅ 3a) ⋅ 4
5(3a ⋅ 4) = 5 ⋅ 3a ⋅ 4