Answer:
Slope is defined as the difference in the vertical axis divided by the difference in the horizontal axis, going left to right (s = dy/dx). P has a lesser x co-ordinate, so it will be R - P in this case, giving us (ry - py) / (rx - px):
[tex]s = \frac{{\Delta}y}{{\Delta}x}[/tex]
[tex]s = \frac{73 - 9}{57 - 4}[/tex]
[tex]s = 64/53[/tex]
