Question

Simplificar: (a + 4)! / (a+3)! = 10

Answer 1

Utilizaremos lo siguiente

$n!=n(n-1)!$

$\dfrac{(a+4)!}{(a+3)!}=10\\\\\\\dfrac{(a+4)(a+3)!}{(a+3)!}=10\\\\\\a+4=10\\\\\boxed{a=6}$