permutari de 5 +aranjamente de 3 luate cate 2

Răspuns :

5! + 3!/1! =1*2*3*4*5 + 1*2*3 / 1 = 120+6=126.
P5=5!=120
[tex] A_{3}^{2} = \frac{3!}{(3-2)!} = \frac{1*2*3}{1} =6[/tex]
120+6=126