sprawdzić czy jest prawdziwa równość(bez kalkulatora)
: 4 mar 2019, o 00:09
\(\displaystyle{ a)}\) \(\displaystyle{ {20\choose 10}}\) \(\displaystyle{ +}\) \(\displaystyle{ {20\choose 11}}\) \(\displaystyle{ =}\) \(\displaystyle{ {21\choose 10}}\)
\(\displaystyle{ b)}\) \(\displaystyle{ {20\choose 6}}\) \(\displaystyle{ +}\) \(\displaystyle{ {20\choose 7}}\) \(\displaystyle{ =}\) \(\displaystyle{ {21\choose 6}}\)
\(\displaystyle{ b)}\) \(\displaystyle{ {20\choose 6}}\) \(\displaystyle{ +}\) \(\displaystyle{ {20\choose 7}}\) \(\displaystyle{ =}\) \(\displaystyle{ {21\choose 6}}\)