Write the property that justifies each mathematical statement. Look carefully!!
1. a(cd) = ac - ad
2. 2x + y = y + 2x
3. — 3(4c) = (- 3 * 4)c
4. 3(4ab) = (4ab)3
5. - 9(3 + 2x) = -9(3) - 9(2x)
6. 3+ (2 + n) = (3 + 2) + n