The slope, commonly abbreviated as
, is the change in the quantity on the y-axis, Δy, divided by the change in the quantity on the x-axis, Δx.
![m = \frac{\Delta y}{\Delta x} = \frac{y2 - y1}{x2 - x1}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7B%5CDelta%20y%7D%7B%5CDelta%20x%7D%20%3D%20%5Cfrac%7By2%20-%20y1%7D%7Bx2%20-%20x1%7D)
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
![m = \frac{y2-y1}{x2-x1} = \frac{-7-(-3)}{4-8} = \frac{-7 + 3}{-4} = \frac{-4}{-4} = 1](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7By2-y1%7D%7Bx2-x1%7D%20%3D%20%5Cfrac%7B-7-%28-3%29%7D%7B4-8%7D%20%3D%20%5Cfrac%7B-7%20%2B%203%7D%7B-4%7D%20%3D%20%5Cfrac%7B-4%7D%7B-4%7D%20%3D%201)
So the slope,
, is equal to 1.