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

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

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  1. Đáp án:

     \(2^{10}\)

    Giải thích các bước giải:

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

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