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  • Biết Tuốt
    Biết Tuốt

    1. {4.2^3}:\left( {{2^7}.\dfrac{1}{{32}}} \right) = {4.2^3}:\left( {{2^7}.\dfrac{1}{{{2^5}}}} \right) = {2^2}{.2^3}:\dfrac{{{2^7}}}{{{2^5}}} = {2^5}:{2^2} = {2^3}

    \begin{array}{l} \dfrac{{11}}{{15}}.\dfrac{{12}}{{13}} - \dfrac{7}{{30}} + \dfrac{{11}}{{15}}.\dfrac{{14}}{{13}} = \dfrac{{11}}{{15}}.\left( {\dfrac{{12}}{{13}} + \dfrac{{14}}{{13}}} \right) - \dfrac{7}{{30}}\\ = \dfrac{{11}}{{15}}.2 - \dfrac{7}{{30}} = \dfrac{{22}}{{15}} - \dfrac{7}{{30}} = \dfrac{{44}}{{30}} - \dfrac{7}{{30}} = \dfrac{{37}}{{30}} \end{array}

    \begin{array}{l} \dfrac{5}{{13}} + \dfrac{{ - 5}}{{17}} + \dfrac{{ - 21}}{{41}} + \dfrac{8}{{13}} + \dfrac{{ - 20}}{{41}}\\ = \left( {\dfrac{5}{{13}} + \dfrac{8}{{13}}} \right) + \dfrac{{ - 5}}{{17}} + \left( {\dfrac{{ - 21}}{{41}} + \dfrac{{ - 20}}{{41}}} \right) = 1 + \dfrac{{ - 5}}{{17}} + \left( { - 1} \right) = \dfrac{{ - 5}}{{17}} \end{array}

    \dfrac{4}{9} + \dfrac{{23}}{{37}} - \dfrac{{22}}{9} + \dfrac{{14}}{{37}} + {1^3} = \left( {\dfrac{4}{9} - \dfrac{{22}}{9}} \right) + \left( {\dfrac{{23}}{{37}} + \dfrac{{14}}{{37}}} \right) + {1^3} = \dfrac{{ - 18}}{9} + 1 + 1 = - 2 + 2 = 0

    \dfrac{2}{5} + \dfrac{3}{5}:\left( {\dfrac{{ - 3}}{2}} \right) + \dfrac{1}{2} - \dfrac{{1001}}{{2002}} = \dfrac{2}{5} + \dfrac{3}{5}.\left( {\dfrac{{ - 2}}{3}} \right) + \dfrac{1}{2} - \dfrac{1}{2} = \dfrac{2}{5} - \dfrac{2}{5} + \dfrac{1}{2} - \dfrac{1}{2} = 0

    \dfrac{2}{5} + \dfrac{3}{5}:\left( {\dfrac{{ - 3}}{2}} \right) + \dfrac{1}{2} - \dfrac{{1001}}{{2002}} = \dfrac{2}{5} + \dfrac{3}{5}.\left( {\dfrac{{ - 2}}{3}} \right) + \frac{1}{2} - \dfrac{1}{2} = \dfrac{2}{5} - \dfrac{2}{5} + \frac{1}{2} - \dfrac{1}{2} = 0

    \begin{array}{l} \dfrac{8}{{15}}.\dfrac{{ - 4}}{9} + \dfrac{8}{{15}}:\dfrac{{ - 9}}{5} - 3\dfrac{2}{5} = \dfrac{8}{{15}}.\dfrac{{ - 4}}{9} + \dfrac{8}{{15}}.\dfrac{{ - 5}}{9} - 3\dfrac{2}{5} = \dfrac{8}{{15}}.\left( {\frac{{ - 4}}{9} + \dfrac{{ - 5}}{9}} \right) - 3\dfrac{2}{5}\\ = \dfrac{8}{{15}}.\left( { - 1} \right) - 3\dfrac{2}{5} = \dfrac{{ - 8}}{{15}} - \dfrac{{17}}{5} = \dfrac{{ - 8}}{{15}} - \dfrac{{51}}{{15}} = - \dfrac{{59}}{{15}} \end{array}

    \left( {\dfrac{{ - 2}}{3} + \dfrac{3}{{13}}} \right):\dfrac{7}{8} + \left( {\dfrac{{ - 1}}{3} + \dfrac{{10}}{{13}}} \right):\dfrac{7}{8} = \left( {\dfrac{{ - 2}}{3} + \dfrac{3}{{13}} + \dfrac{{ - 1}}{3} + \dfrac{{10}}{{13}}} \right):\dfrac{7}{8} = 0.\dfrac{7}{8} = 0

    \begin{array}{l} \dfrac{{15}}{{37}}.\left( {\dfrac{{38}}{{41}} - \dfrac{{74}}{{45}}} \right) - \dfrac{{38}}{{41}}\left( {\dfrac{{15}}{{37}} + \dfrac{{82}}{{76}}} \right) = \dfrac{{15}}{{37}}.\dfrac{{38}}{{41}} - \dfrac{{15}}{{37}}.\dfrac{{74}}{{45}} - \dfrac{{38}}{{41}}.\dfrac{{15}}{{37}} - \dfrac{{38}}{{41}}\dfrac{{82}}{{76}}\\ = \dfrac{{15}}{{37}}.\dfrac{{38}}{{41}} - \dfrac{{38}}{{41}}.\dfrac{{15}}{{37}} - \dfrac{{15}}{{37}}.\dfrac{{74}}{{45}} - \dfrac{{38}}{{41}}\dfrac{{82}}{{76}} = - \dfrac{{15}}{{37}}.\dfrac{{74}}{{45}} - \dfrac{{38}}{{41}}\dfrac{{82}}{{76}} = \dfrac{{ - 5}}{3} \end{array}

    \begin{array}{l} \dfrac{5}{7}\left( {\dfrac{1}{2} - \dfrac{1}{3} + \dfrac{4}{7}} \right) + \left( {\dfrac{1}{3} - \dfrac{1}{2} - \dfrac{4}{7}} \right):\dfrac{7}{5} = \dfrac{5}{7}\left( {\dfrac{1}{2} - \dfrac{1}{3} + \dfrac{4}{7}} \right) + \left( {\dfrac{1}{3} - \dfrac{1}{2} - \dfrac{4}{7}} \right).\dfrac{5}{7}\\ = \dfrac{5}{7}\left( {\dfrac{1}{2} - \dfrac{1}{3} + \dfrac{4}{7} + \dfrac{1}{3} - \dfrac{1}{2} - \dfrac{4}{7}} \right) = \dfrac{5}{7}.0 = 0 \end{array}

    \dfrac{5}{7}:\left( {\dfrac{{15}}{8} - \dfrac{1}{4}} \right) - \dfrac{5}{7}:\left( {\dfrac{1}{4} + \dfrac{1}{2}} \right) = \dfrac{5}{7}:\left( {\dfrac{{15}}{8} - \dfrac{1}{4} - \dfrac{1}{4} - \dfrac{1}{2}} \right) = \dfrac{5}{7}:\dfrac{7}{8}

    0 Trả lời 27/10/22
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