Answer:
c. 2520
Explanation:
Repetition is not allowed, therefore:
1st digit can be any of the given 7 numbers
2nd digit can be any of the remaining 6 numbers
3rd digit can be any of the remaining 5 numbers
4th digit can be any of the remaining 4 numbers
5th digit can be any of the remaining 3 numbers
This means that:
number of possible combinations = 7 * 6 * 5 * 4 * 3 = 2520 numbers
Hope this helps :)
For this case we must simplify the following expression:
We eliminate the parentheses taking into account that:

So:

We add similar terms taking into account that:
Equal signs are added and the same sign is placed.
Different signs are subtracted and the major sign is placed.

Answer:
