The slope, commonly abbreviated as [tex]m[/tex], is the change in the quantity on the y-axis, Δy, divided by the change in the quantity on the x-axis, Δx.
[tex]m = \frac{\Delta y}{\Delta x} = \frac{y2 - y1}{x2 - x1}[/tex]
From the points (x, y), the first value is a value on the x-axis, and the second value after the comma is a value on the y-axis. So for the point (8, -3), 8 is x and -3 is y. But we have two points, so:
(8, -3), 8 is x1, -3 is y1
(4, -7), 4 is x2, -7 is y2
Plugging in our values, we get
[tex]m = \frac{y2-y1}{x2-x1} = \frac{-7-(-3)}{4-8} = \frac{-7 + 3}{-4} = \frac{-4}{-4} = 1[/tex]
So the slope, [tex]m[/tex], is equal to 1.
