1. The problem is to subtract the fractions $-\frac{3}{5}$ and $\frac{4}{5}$. 2. Since both fractions have the same denominator, we can subtract the numerators directly: $$-\frac{3}{5} - \frac{4}{5} = \frac{-3 - 4}{5}$$ 3. Simplify the numerator: $$\frac{-3 - 4}{5} = \frac{-7}{5}$$ 4. The result is $-\frac{7}{5}$, which is an improper fraction and can also be written as $-1\frac{2}{5}$. Therefore, the final answer is $-\frac{7}{5}$ or $-1\frac{2}{5}$.