What is the slope of the line through (1, 3) and (4, 11)?

• A. 8/3
• B. 3/8
• C. 4/7
• D. -8/3

Answer: (A)

Slope is the rate of change: how much y increases (or decreases) for each unit x moves to the right. Between the points, the rise is 11 minus 3 = 8 and the run is 4 minus 1 = 3, so the slope is 8/3. This is positive, meaning the line goes up as you move to the right. A common slip is using the reciprocal (3/8) or a negative slope; those would imply different changes not shown by these coordinates.