Stephen's calculation for slope is incorrect. The correct formula for the slope (m) is given by:
\[ m = \frac{\Delta y}{\Delta x} = \frac{y_2 - y_1}{x_2 - x_1} \]
In this case, we can identify the points as follows:
- \( (x_1, y_1) = (8, -6) \)
- \( (x_2, y_2) = (0, 8) \)
Now, substituting the values into the slope formula:
-
Calculate \( \Delta y \): \[ y_2 - y_1 = 8 - (-6) = 8 + 6 = 14 \]
-
Calculate \( \Delta x \): \[ x_2 - x_1 = 0 - 8 = -8 \]
Now, we can compute the slope: \[ m = \frac{14}{-8} = -\frac{7}{4} \]
From this calculation, we conclude that Stephen's error comes from using incorrect values and the wrong steps in his calculation. Thus, the correct statement would be:
Stephen is incorrect because he added instead of subtracted.