In the following example of "Simplifying an Expression", what reason would be used for step D?

Simplify the expression 3k + 7 + 2k and justify each step

3k + 7 + 2k = 3k + 2k + 7 A
= (3k + 2k) + 7 B
= (3 + 2)k + 7 C
= 5k + 7 D
A. Addition
B. Commutative Property
C. Associative Property
D. Distributive Property In the following example of "Simplifying an Expression", what reason would be used for step D?

Simplify the expression 3k + 7 + 2k and justify each step

3k + 7 + 2k = 3k + 2k + 7

Question

In the following example of "Simplifying an Expression", what reason would be used for step D?

Simplify the expression 3k + 7 + 2k and justify each step

3k + 7 + 2k = 3k + 2k + 7         A
                    = (3k + 2k) + 7      B
                    = (3 + 2)k + 7        C
                    = 5k + 7                 D
	A.	Addition
	B.	Commutative Property
	C.	Associative Property
	D.	Distributive Property In the following example of "Simplifying an Expression", what reason would be used for step D?

Simplify the expression 3k + 7 + 2k and justify each step

3k + 7 + 2k = 3k + 2k + 7

anonymous · Answer

5k +7

zepdrix · Answer

So in step D, it looks like they simply ADDED the 3 and 2.
Hmmmm.