Odpowiedź :
[tex]\displaystyle\\\binom{9}{2}+\binom{9}{3}=\dfrac{9!}{2!7!}+\dfrac{9!}{3!6!}=\dfrac{8\cdot9}{2}+\dfrac{7\cdot8\cdot9}{2\cdot3}=36+84=120[/tex]
[tex]\displaystyle\\\binom{9}{2}+\binom{9}{3}=\dfrac{9!}{2!7!}+\dfrac{9!}{3!6!}=\dfrac{8\cdot9}{2}+\dfrac{7\cdot8\cdot9}{2\cdot3}=36+84=120[/tex]