Deret Khusus

KOMBINASI

$$\sum _{k=0}^n(\genfrac{}{}{0ex}{}{n}{k})a^{n-k}{b}^k=(a+b{)}^n$$

$$\sum _{k=0}^n(\genfrac{}{}{0ex}{}{n}{k})=(\genfrac{}{}{0ex}{}{n}{0})+(\genfrac{}{}{0ex}{}{n}{1})+\cdots +(\genfrac{}{}{0ex}{}{n}{n})=2^n$$