Answer: 
Step-by-step explanation:
1. By definition, the associative property of addition is:

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:

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

3. Then, you can conclude that the correct option is B.
Answer:
k=-1827/685
Step-by-step explanation:
8/9k+9/5=-4-9/7k
8/9k-(-9/7k)=-4-9/5
8/9k+9/7k=-20/5-9/5
56/63k+81/63k=-29/5
137/63k=-29/5
k=(-29/5)/(137/63)
k=(-29/5)(63/137)
k=-1827/685
The band has sold 1,890,000 copies or 1.89 x 10^6