Answer: By

Step-by-step explanation:
You need to analize the information provided in the exercise.
You know that:
1. The value of a stock increases 1,423 points twice in one week. This indicates that you must multiply 1,423 points by 2:

2. The other three days the value decreases by 10 points, 813 points, and 1,223 points. So you need to find the sum. This is:

Finally, you need to subtract 2,846 points and 2,046 points in order to calculate by how many points the value of the stock changed that week.
Therefore, the result is:
