The point-slope form of a line is given by the equation:
\[ y - y_1 = m(x - x_1) \]
where \( m \) is the slope, and \( (x_1, y_1) \) is a point on the line.
Given that the slope \( m \) is 15 and the point \( (3, -1) \) is on the line, we can substitute these values into the point-slope formula:
\[ y - (-1) = 15(x - 3) \]
This simplifies to:
\[ y + 1 = 15(x - 3) \]
Thus, the equation of the line in point-slope form is:
\[ y + 1 = 15(x - 3) \]