cách giải 11C6+11C7+11C8+11C9+11C10+11C11=

Đáp án:

 \(2^{10}\)

Giải thích các bước giải:

$\begin{array}{l}
{\left( {1 + 1} \right)^{11}} = C_{11}^0 + C_{11}^1 + C_{11}^2 + C_{11}^3 + C_{11}^4 + C_{11}^5\\
 + C_{11}^6 + C_{11}^7 + C_{11}^8 + C_{11}^9 + C_{11}^{10} + C_{11}^{11}\\
 \Leftrightarrow {2^{11}} = C_{11}^{11} + C_{11}^{10} + C_{11}^9 + C_{11}^8 + C_{11}^7 + C_{11}^6\\
 + C_{11}^6 + C_{11}^7 + C_{11}^8 + C_{11}^9 + C_{11}^{10} + C_{11}^{11}\\
 \Leftrightarrow {2^{11}} = 2\left( {C_{11}^6 + C_{11}^7 + C_{11}^8 + C_{11}^9 + C_{11}^{10} + C_{11}^{11}} \right)\\
 \Leftrightarrow C_{11}^6 + C_{11}^7 + C_{11}^8 + C_{11}^9 + C_{11}^{10} + C_{11}^{11} = {2^{11}}:2\\
 \Leftrightarrow C_{11}^6 + C_{11}^7 + C_{11}^8 + C_{11}^9 + C_{11}^{10} + C_{11}^{11} = {2^{10}}
\end{array}$

Đáp án:

 2^10

Giải thích các bước giải: