Question

A7,4 analise combinatoria

Answer 1

$A_{7,4}=\dfrac{7!}{(7-4)!}\\\\\\A_{7,4}}=\dfrac{7!}{3!}\\\\\\A_{7,4}=\dfrac{7\cdot6\cdot5\cdot4\cdot3!}{3!}\\\\\\A_{7,4}=7\cdot6\cdot5\cdot4\\\\\boxed{A_{7,4}=840}$