To simplify the expression \(-\frac{5}{18} + \frac{5}{45} - \frac{9}{6}\), we need to find a common denominator for the fractions. The denominators are 18, 45, and 6. The least common multiple (LCM) of these numbers is 90.

First, we convert each fraction to have a denominator of 90:

1. \(-\frac{5}{18}\):
\[
-\frac{5}{18} = -\frac{5 \times 5}{18 \times 5} = -\frac{25}{90}
\]

2. \(\frac{5}{45}\):
\[
\frac{5}{45} = \frac{5 \times 2}{45 \times 2} = \frac{10}{90}
\]

3. \(-\frac{9}{6}\):
\[
-\frac{9}{6} = -\frac{9 \times 15}{6 \times 15} = -\frac{135}{90}
\]

Now, we can combine the fractions:
\[
-\frac{25}{90} + \frac{10}{90} - \frac{135}{90}
\]

Combine the numerators over the common denominator:
\[
\frac{-25 + 10 - 135}{90} = \frac{-150}{90}
\]

Simplify the fraction by dividing the numerator and the denominator by their greatest common divisor (GCD), which is 30:
\[
\frac{-150 \div 30}{90 \div 30} = \frac{-5}{3}
\]

So, the simplified form of the expression \(-\frac{5}{18} + \frac{5}{45} - \frac{9}{6}\) is:
\[
-\frac{5}{3}
\]