\(M=\frac{5}{7}\left(\frac{8}{5}+\frac{2}{5}\right)+\frac{5}{7}\left(\frac{6}{5}+\frac{9}{5}\right)\)
Cách 1 : \(M=\frac{5}{7}\left(\frac{8}{5}+\frac{2}{5}\right)+\frac{5}{7}\left(\frac{6}{5}+\frac{9}{5}\right)\)
\(M=\frac{5}{7}\cdot\left(\frac{8}{5}+\frac{2}{5}+\frac{6}{5}+\frac{9}{5}\right)=\frac{5}{7}.\frac{25}{5}=\frac{25}{7}\)
Cách 2:
\(M=\frac{5}{7}\left(\frac{8}{5}+\frac{2}{5}\right)+\frac{5}{7}\left(\frac{6}{5}+\frac{9}{5}\right)\)
\(M=\frac{10}{5}.\frac{5}{7}+\frac{15}{5}.\frac{5}{7}=\frac{10}{7}+\frac{15}{7}=\frac{25}{7}\)
Cách 3 :
\(M=\frac{5}{7}\left(\frac{8}{5}+\frac{2}{5}\right)+\frac{5}{7}\left(\frac{6}{5}+\frac{9}{5}\right)\)
\(M=\frac{8}{5}.\frac{5}{7}+\frac{2}{5}.\frac{5}{7}+\frac{6}{5}.\frac{5}{7}+\frac{9}{5}.\frac{5}{7}=\frac{8}{7}+\frac{2}{7}+\frac{6}{7}+\frac{9}{7}=\frac{25}{7}\)
Cách 1 :
\(M=\left(\frac{8}{5}+\frac{2}{5}\right).\frac{5}{7}+\left(\frac{6}{5}+\frac{9}{5}\right).\frac{5}{7}\)
\(M=2.\frac{5}{7}+3.\frac{5}{7}\)
\(M=\frac{10}{7}+\frac{15}{7}\)
\(M=\frac{25}{7}\)
Cách 2
\(M=\left(\frac{8}{5}+\frac{2}{5}\right).\frac{5}{7}+\left(\frac{6}{5}+\frac{9}{5}\right).\frac{5}{7}\)
\(M=2.\frac{5}{7}+3.\frac{5}{7}\)
\(M=\left(2+3\right).\frac{5}{7}\)
\(M=5.\frac{5}{7}\)
\(M=\frac{25}{7}\)
Cách 3 :
\(M=\left(\frac{8}{5}+\frac{2}{5}\right).\frac{5}{7}+\left(\frac{6}{5}+\frac{9}{5}\right).\frac{5}{7}\)
\(M=\left[\left(\frac{8}{5}+\frac{2}{5}\right)+\left(\frac{6}{5}+\frac{9}{5}\right)\right].\frac{5}{7}\)
\(M=\left[2+3\right].\frac{5}{7}\)
\(M=5.\frac{5}{7}\)
\(M=\frac{25}{7}\)
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