Finding the Slope of a Linear Function

If $f (x)$ is a linear function, and $(3, −2)$ and $(8, 1)$ are points on the line, find the slope. Is this function increasing or decreasing?

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Solution
The coordinate pairs are $(3, −2)$ and $(8, 1) .$ To find the rate of change, we divide the change in output by the change in input.
$m = \frac{change in output}{change in input} = \frac{1 - (−2)}{8 - 3} = \frac{3}{5}$
We could also write the slope as $m = 0.6.$ The function is increasing because $m > 0.$

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

If $f (x)$ is a linear function, and $(2, 3)$ and $(0, 4)$ are points on the line, find the slope. Is this function increasing or decreasing?

How did it go?