Question

What is this?

Answer 1

@Vocaloid This is some foreign algebra

Answer 2

@sillybilly123

Answer 3

permutations?

Answer 4

I have no idea. I am helping someone and they say it is old work and don't know what lesson it is from.

Answer 5

Say you have 3 items

how many ways can you combine them? \(\text{}^3C_3 = 1\)

how many ways can you permute (ie ORDER) them? \(\text{}^3P_3 = 6\)

Combinatorics ..... Pascal's Triangle .... etc

Answer 6

it's mental

Answer 7

mhm

Answer 8

but it's all different ways of collecting 1,2,3

Answer 9

and order doesn't really matter in the end :)

Answer 10

except you arrive at cool formulae that make math easier.

eg:

\(\text{}^nC_r = \dfrac{n!}{(n-r)! ~ r!}\)