Răspuns :
[tex]C^3_7 = C^{(7-3)}_7= C^4_7 = \frac{7!}{3! * 4!}= \\ =\frac{1*2*3*4*5*6*7}{1*2*3*1*2*3*4}= \frac{5*6*7}{1*2*3}= \\ = \frac{5*6*7}{6}=5*7=35[/tex]
Daca te referi la combinari de 7 luate cite trei atunci rezulta
[tex] \frac{7!}{3!(7-3)!} =35[/tex]
[tex] \frac{7!}{3!(7-3)!} =35[/tex]