To multiply \( \frac{4}{5} \) by \(-9\), you can treat \(-9\) as a fraction by writing it as \(-\frac{9}{1}\).
Now, multiply the fractions:
\[ \frac{4}{5} \times -\frac{9}{1} = \frac{4 \times -9}{5 \times 1} = \frac{-36}{5} \]
So, \( \frac{4}{5} \times -9 = -\frac{36}{5} \) or \(-7.2\) in decimal form.