Question

Thực hiện phép tính

(2/3 - 4/7) : 5/9 + (-8/7 + 1/3) : 5/9

Answer 1

\(\left(\frac{2}{3}-\frac{4}{7}\right):\frac{5}{9}+\left(-\frac{8}{7}+\frac{1}{3}\right):\frac{5}{9}\)

\(=\left[\left(\frac{2}{3}-\frac{4}{7}\right)+\left(-\frac{8}{7}+\frac{1}{3}\right)\right]:\frac{5}{9}\)

\(=\left(\frac{2}{3}-\frac{4}{7}-\frac{8}{7}+\frac{1}{3}\right)\cdot\frac{9}{5}\)

\(=\left(1-\frac{12}{7}\right)\cdot\frac{9}{5}\)

\(=-\frac{5}{7}\cdot\frac{9}{5}\)

\(-\frac{9}{7}\)

Answer 2

\(\left(\frac{2}{3}-\frac{4}{7}\right):\frac{5}{9}+\left(-\frac{8}{7}+\frac{1}{3}\right):\frac{5}{9}\)

\(=\left(\frac{14}{21}-\frac{12}{21}\right):\frac{5}{9}+\left(-\frac{24}{21}+\frac{7}{21}\right):\frac{5}{9}\)

\(=\frac{2}{21}:\frac{5}{9}+\frac{-17}{21}:\frac{5}{9}\)

\(=\left(\frac{2}{21}+\frac{-17}{21}\right):\frac{5}{9}\)

\(=\frac{-15}{21}:\frac{5}{9}\)

\(=\frac{-15}{21}.\frac{9}{5}\)

\(=\frac{-9}{7}\)

\(=\frac{99}{35}\)