Question

Resolva a equação :
$A_{x,1} - 1 +4X = P_{3} + C_{8,1}$

Answer 1

Olá!!

$\\ \displaystyle \mathsf{A_{x, 1} - 1 + 4x = P_3 + C_{8, 1}} \\\\\\ \mathsf{\frac{x!}{(x - 1)!} - 1 + 4x = 3! + \frac{8!}{7!1!}} \\\\\\ \mathsf{\frac{x \cdot (x - 1)!}{(x - 1)!} - 1 + 4x = 3 \cdot 2 \cdot 1 + \frac{8 \cdot 7!}{7!1!}} \\\\\\ \mathsf{\frac{x!}{(x - 1)!} - 1 + 4x = 3! + \frac{8!}{7!1!}} \\\\\\ \mathsf{x - 1 + 4x = 6 + 8} \\\\ \mathsf{5x = 15} \\\\ \boxed{\mathsf{x = 3}}$