Question

Tính bằng cách thuận tiện :

1) \(\frac{2}{3}+\left(\frac{5}{14}+\frac{-25}{23}\right)-\left(\frac{-2}{23}-\frac{9}{14}\right)\)

Answer 1

phá ngoặc ra ~~

Answer 2

1) \(\frac{2}{3}+\left(\frac{5}{14}+\frac{-25}{23}\right)-\left(\frac{-2}{23}-\frac{9}{14}\right)\)

= \(\frac{2}{3}+\frac{5}{14}+\frac{-25}{23}-\frac{-2}{23}+\frac{9}{14}\)

= \(\frac{-25}{23}+\frac{2}{23}+\left(\frac{5}{14}+\frac{9}{14}\right)+\frac{2}{3}\)

= \(-\frac{23}{23}+\frac{14}{14}+\frac{2}{3}\)

= \(-1+1+\frac{2}{3}\)

= 0 + \(\frac{2}{3}\)

= \(\frac{2}{3}\)

Answer 3

\(\frac{2}{3}+\left(\frac{5}{14}+\frac{-25}{23}\right)-\left(\frac{-2}{23}-\frac{9}{14}\right)\) \(=\frac{2}{3}+\frac{5}{14}+\frac{-25}{23}+\frac{2}{23}+\frac{9}{14}\) \(=\frac{2}{3}+\left(\frac{5}{14}+\frac{9}{14}\right)+\left(\frac{-25}{23}+\frac{2}{23}\right)\) \(=\frac{2}{3}+1-1\) =\(\frac{2}{3}\)