Question

análise combinatória C 7,2​

Answer 1

$C_{n,m}~=~\dfrac{n!}{m!\,.\,(n-m)!}\\\\\\\\C_{7,2}~=~\dfrac{7!}{2!\,.\,(7-2)!}\\\\\\\\C_{7,2}~=~\dfrac{7~.~6~.~5!}{2~.~5!}\\\\\\\\C_{7,2}~=~\dfrac{7~.~6\!\!\!\backslash~.~5\!\!\!\backslash!}{2\!\!\!\backslash~.~5\!\!\!\backslash!}\\\\\\\\C_{7,2}~=~\dfrac{7~.~3~.~1}{1~.~1}\\\\\\\\\boxed{C_{7,2}~=~21}$

Answer 2

resolução!

C7,2 = 7 * 6 / 2!

C7,2 = 42 / 2

C7,2 = 21