bài 1 a) (5.3/7)^4 b) (2/3:5/6)^3 bài 2 230^5/23^5 Bài 3 a)21^30/63^15 b)28^9.30^9/105^9

0 bình luận về “bài 1 a) (5.3/7)^4 b) (2/3:5/6)^3 bài 2 230^5/23^5 Bài 3 a)21^30/63^15 b)28^9.30^9/105^9”

1. Đáp án:

   $\begin{array}{l}
   B1)\\
   a){\left( {\dfrac{{5.3}}{7}} \right)^4} = \dfrac{{{{15}^4}}}{{{7^4}}}\\
   b){\left( {\dfrac{2}{3}:\dfrac{5}{6}} \right)^3}\\
    = {\left( {\dfrac{2}{3}.\dfrac{6}{5}} \right)^3}\\
    = {\left( {\dfrac{4}{5}} \right)^3} = \dfrac{{64}}{{125}}\\
   B2)\\
   \dfrac{{{{230}^5}}}{{{{23}^5}}} = {\left( {\dfrac{{23.10}}{{23}}} \right)^5} = {10^5} = 100000\\
   B3)\\
   a)\dfrac{{{{21}^{30}}}}{{{{63}^{15}}}} = \dfrac{{{{\left( {3.7} \right)}^{30}}}}{{{{\left( {{3^2}.7} \right)}^{15}}}} = \dfrac{{{3^{30}}{{.7}^{30}}}}{{{3^{30}}{{.7}^{15}}}} = {7^{15}}\\
   b)\dfrac{{{{28}^9}{{.30}^9}}}{{{{105}^9}}} = \dfrac{{{{\left( {{2^2}.7} \right)}^9}.{{\left( {2.3.5} \right)}^9}}}{{{{\left( {3.5.7} \right)}^9}}}\\
    = \dfrac{{{2^{18}}{{.7}^9}{{.2}^9}{{.3}^9}{{.5}^9}}}{{{3^9}{{.5}^9}{{.7}^9}}}\\
    = {2^{27}}
   \end{array}$

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