Question

(6 + 7) + 8 = 21

Choose an equivalent addition sentence that shows the associative property of addition.
A.
(6 + 7) + 8 = 21
B.
6 + (7 + 8) = 21
C.
6 + 7 + 8 = 21
D.
21 = (6 + 7) + 8

Answer 1

Answer:
`6+(7+8)=21`

Explanation:

1. By definition, the associative property of addition is:

`(a+b)+c=a+(b+c)`

This property says that you can group the numbers in different ways and you will obtain the same result.

2. Therefore, if you have the following expression:

`(6+7)+8=21`

You apply the Asociative property of addition by regrouping the numbers as following:

`6+(7+8)=21`

3. Then, you can conclude that the correct option is B.