Question

Calculati 7! supra 3!*5! + 9! Supra 2!*7!
Am făcut rezolvarea și as vrea sa văd dacă este bine. Mulțumesc de ajutor !

Answer 1

$\frac{7!}{3! \times 5!} + \frac{9!}{2! \times 7!}$

$= \frac{1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7}{1 \times 2 \times 3 \times 1 \times 2 \times 3 \times 4 \times 5} + \frac{1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7 \times 8 \times 9}{1 \times 2 \times 1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7}$

$= \frac{6 \times 7}{1 \times 2 \times 3} + \frac{8 \times 9}{1 \times 2 }$

$= \frac{42}{6} + \frac{72}{2}$

$= 7 + 36$

$= 43$