Question

Ajutor please îmi trebuie până mâine dau coroana la cine raspunde​

Answer 1

Formule:

$P_{n} =n!$

$C^{k}_{n} =\frac{n!}{k!(n-k)!}$

$A^{k}_{n}=\frac{n!}{(n-k)!}$

Rezolvare:

a) $P_{3}$ =3! = 1 * 2 * 3 = 6

b)$P_{5}+P_{2} =$5! + 2! = 120+2=122

c) $C^{2}_{6}=$$\frac{6!}{2! * 4!}$  $=\frac{5 * 6}{1 * 2} = 5 *3 = 15$

d) $A^{2}_{7}= \frac{7!}{5!} = 6 *7=42$

e) $P_{4}+10=4!+10=1 *2*3*4+10=24+10=34$

f) $A_{5} ^{2} + P_{3}= \frac{5!}{3!} + 1*2*3=4*5+6=26$

g)$C^{1}_{5}+C^{2}_{5}=5+\frac{4*5}{2} =5+10=15$

h) $\frac{7!}{3!*4!} - \frac{4!}{1!*3!} = \frac{5*6*7}{2*3}-4=35-4=31$

i) $\frac{10!}{9!*1!} + \frac{4!}{2!} = 10 +12=22$