To find the slope of the line given by the equation \( y - 3 = -\frac{5}{4} (x - 15) \), we can identify the slope directly from the equation, which is in point-slope form:
\[ y - y_1 = m(x - x_1) \]
where \( m \) is the slope and \( (x_1, y_1) \) is a point on the line.
From the equation you provided:
- The slope \( m = -\frac{5}{4} \)
- The point is \( (15, 3) \)
Thus, the slope of the line is:
\[ \text{slope} = -\frac{5}{4} \]