To evaluate \(-\frac{5}{6} + \left(-\frac{1}{3}\right)\), we first need to make the denominators the same.
The fraction \(-\frac{1}{3}\) can be converted to a fraction with a denominator of 6:
\[ -\frac{1}{3} = -\frac{2}{6} \]
Now we can rewrite the original expression:
\[ -\frac{5}{6} + \left(-\frac{2}{6}\right) = -\frac{5}{6} - \frac{2}{6} \]
Next, we add the fractions:
\[ -\frac{5 + 2}{6} = -\frac{7}{6} \]
Thus, the final result is:
\[ -\frac{7}{6} \]
Looking at the provided responses, the correct answer is:
A \(-\frac{7}{6}\)