Answer:
1. Commutative Property of Multiplication
2. Commutative Property of multiplication
3. Transitive Property of equality
4. Associative Property of Addition
Step-by-step explanation:
1) (15 * 12x) * y = y * (15 * 12x) a*(b*c) = (b*c)*a
2) 22x * (3 * 4y) = 22x * (4y * 3) a*(b*c) = a*(c*b)
3) If x = 4 and 4 = y, then x = y If a=b and b=c then a=c
4) (7x + 15) + 21 = 7x + (15 + 21) (a+b) +c = a+(b+c)
