What is the slope of the line passing through (-3, 5) and (5, -3)?

Dy/dx, ie., the difference in y divided by the difference in x. If you have two points A and B, sort them in ascending order of x.

dx = 5 - -3 = 8 (x coordinates of B minus x coordinate of A)
dy = -3 - 5 = -8 (y coordinate of B minus y coordinate of A)

dy/dx = -1

So the slope is -1. The equation of the line is y=2-x.