To add the two fractions, we need to find a common denominator. The common denominator for the fractions \(\frac{-4}{x-1}\) and \(\frac{-3}{x+2}\) is \((x-1)(x+2)\). Once we have the common denominator, we can rewrite each fraction with this denominator and then add the numerators.
Step 1: Finding a Common Denominator
To add the fractions \(\frac{-4}{x-1}\) and \(\frac{-3}{x+2}\), we first identify the common denominator, which is \((x-1)(x+2)\).
Step 2: Rewriting the Fractions
We rewrite each fraction with the common denominator:
\[
\frac{-4}{x-1} = \frac{-4(x+2)}{(x-1)(x+2)} = \frac{-4x - 8}{(x-1)(x+2)}
\]
\[
\frac{-3}{x+2} = \frac{-3(x-1)}{(x-1)(x+2)} = \frac{-3x + 3}{(x-1)(x+2)}
\]
Step 3: Adding the Fractions
Now we can add the two fractions:
\[
\frac{-4x - 8}{(x-1)(x+2)} + \frac{-3x + 3}{(x-1)(x+2)} = \frac{(-4x - 8) + (-3x + 3)}{(x-1)(x+2)} = \frac{-7x - 5}{(x-1)(x+2)}
\]
Final Answer
The result of adding the fractions is:
\[
\boxed{\frac{-7x - 5}{(x-1)(x+2)}}
\]