On a graph, slope measures the change in for each unit of change in . Read two points you can locate exactly, then put the change in over the change in . Subtract in the same order for both changes: a line that falls as you move right must have a negative slope.
Hints
- Hint 1
A point’s coordinates give its horizontal position first and vertical position second. Read the two solid dots on the graph. As you move from the left dot to the right dot, does rise or fall?
- Hint 2
The slope is the change in divided by the change in , not either change alone. Subtract the points in the same order on top and bottom. What fraction does that give you?
Step-by-step
Read two points and find the slope
Step 1Read the marked points
Read the two marked points directly from the graph. Their coordinates are and . Moving between the solid dots from left to right, increases while decreases, so expect a negative slope.
- Step 2
Compare the vertical and horizontal changes
The slope is the change in divided by the change in . Subtract in the same order, going from to :
- Step 3
Find the change per unit
Type in Desmos to divide the vertical drop by the horizontal increase. Desmos shows :
So the slope of is : its graph falls unit for each unit you move right. Choice A.