|Step 1) Plot and label 2 points on the line, anywhere on the line. Remember that the slope of a line never changes, so you can choose whatever 2 points you want and you will always get the same slope.
|Step 2) Calculate the rise and run (You can draw it on the graph if it helps).
|Step 3) Use the slope formula
. The slope is 2/4, which , of course, you can simplifty to ½.