To find the slope of the line given the two points \((4, 9)\) and \((5, 0)\), you can use the formula for the slope \(m\):
\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]
Here, \((x_1, y_1) = (4, 9)\) and \((x_2, y_2) = (5, 0)\).
Substituting the values into the slope formula:
\[ m = \frac{0 - 9}{5 - 4} = \frac{-9}{1} = -9 \]
Thus, the slope of the line is \(-9\).
The answer is:
\(-9\)