Let's analyze the options given:
- \(\left[ \frac{2}{5} \right]\)
- \(\left[ -\frac{2}{5} \right]\)
- \(\left[ \frac{2}{5} \right]\)
- \(\left[ \frac{2}{-5} \right]\)
Notice that:
- \(\frac{2}{5}\) is positive.
- \(-\frac{2}{5}\) is the negative of \(\frac{2}{5}\).
- \(\frac{2}{-5}\) is also negative, as it can be simplified to \(-\frac{2}{5}\).
In terms of their values:
- The first and third options represent the same positive value: \(\frac{2}{5}\).
- The second option is negative: \(-\frac{2}{5}\).
- The fourth option is also negative and is equal to the second option: \(-\frac{2}{5}\).
Thus, the choice that is not equal to the others is:
\(\left[ -\frac{2}{5} \right]\)
(as it is the only one that is negative).