ANSWER:
The integer representing the change in number of DVDs sold is -10000.
SOLUTION:
Given, The number of DVDs shipped to an online retailer was 10,000 less than the previous year.
We have to Use an integer to describe the change in the number of DVDs sold.
Now, let the number of DVDs shipped to a online retailer on the previous year be x.
Then, according to the given information, DVDs shipped to the online retailer this year will become x – 10000
So, now, the change in the number of DVDs sold = DVDs sold this year – DVDs sold last year
= x – 10000 – x
= 0 – 10000
= - 10000
Hence, the integer representing the change in number of DVDs sold is -10000.