Question

ME AJUDA POR FAVORRR, É PARA HOJEE​

Answer 1

Resposta:

R: a) 21

R: c) 322

Explicação passo a passo:

$a) \\\\C_{7,5} =\frac{7!}{5!(7-5)!} \\\\\frac{7!}{5!(7-5)!}=\frac{7!}{5!(2)!}\\\\\frac{7!}{5!(2)!}=\frac{7*6*5!}{5!*2*1}\\\\\frac{7*6*5!}{5!*2*1}=\frac{42}{2}=21$

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$b)\\\\2!C_{8,3} + 3!C_{7,4}\\\\2!*\frac{8!}{3!(8-3)!} + 3!*\frac{7!}{4!(7-4)!}\\\\2!*\frac{8*7*6*5!}{6*5!} + 3!*\frac{7*6*5*4!}{4!(3)!}\\\\\\2*8*7+ 7*6*5=322$