To determine if Krystina's calculation for the slope is correct, we should first calculate the slope using the coordinates (6, -2) and (0, 8).
The formula for calculating the slope (m) between two points \((x_1, y_1)\) and \((x_2, y_2)\) is:
\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]
Plugging in the coordinates:
- Let \((x_1, y_1) = (6, -2)\)
- Let \((x_2, y_2) = (0, 8)\)
Now we calculate:
\[ m = \frac{8 - (-2)}{0 - 6} = \frac{8 + 2}{0 - 6} = \frac{10}{-6} = -\frac{5}{3} \]
From this calculation, we see that the correct slope is \(-\frac{5}{3}\).
In Krystina's statement, it looks like she incorrectly manipulated the points and did not follow the correct formula for finding the slope. The specific phrase "slope 3-8-2=2=1" appears to contain errors.
So, addressing the options provided:
-
She is incorrect because she calculated the change in y over change in x: This option aligns with her misunderstanding since she did not calculate it correctly.
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She is correct because she calculated the change in x over the change in y: This option is incorrect; she did not do this.
-
She is incorrect because she calculated change in x over change in y: This option would be wrong, as she incorrectly calculated what should be change in y over change in x.
-
She is correct and she simplified the slope correctly: This option is incorrect as well since she did not arrive at the correct slope.
The most appropriate statement regarding Krystina's mistake is:
She is incorrect because she calculated the change in y over change in x (but note that her calculation was wrong; just indicating she does not have the method correct is key).
Thus, the best option to mark here is:
She is incorrect because she calculated the change in y over change in x.