Answer:
Both, you and your friend, are correct.
Step-by-step explanation:
5 P 5 = 5!
A shortcut I learned is that in the permutation equation nPn when n is the same on both sides, it is equal to if you used factorial, n!.
Step 1. Use the Quotient Rule: x^a/x^b = x^a-b
|-10^5-3|
Step 2. Simplify 5 - 3 to 2
|-10^2|
Step 3. Simplify 10^2 to 100
|-100|
Step 4. Simplify
100
what else? ................
