Respuesta :
The student used a wrong formula to calculate the slope of the line. The slope is: -2.
How to Calculate the Slope of a Line?
The slope of a line is the change in y / change in x, which is the rise of the line over the run of the line. The formula for the slope can be expressed as:
m = [tex]\frac{y_2 - y_1}{x_2 - x_1}[/tex].
Given that a line passes through the points (-3,8) and (2,-4), to find the slope of the line, let:
(-3, 8) = [tex](x_1, y_1)[/tex]
(2, -4) = [tex](x_2, y_2)[/tex]
Substitute the values into m = [tex]\frac{y_2 - y_1}{x_2 - x_1}[/tex].:
Slope of the line (m) = [tex]\frac{y_2 - y_1}{x_2 - x_1}[/tex] = (-4 - 8)/(2 - (-4)) [this is where student made a mistake, he didn't apply the correct slope formula that should be used to find the slope of a line]
Slope of the line (m) = -12/6
Slope of the line (m) = -2
Therefore, we can conclude that the student got a wrong slope value because he didn't apply the right slope formula that is used to find the slope of any given line. The slope for the line should be -2 instead of -11/6.
Learn more about slope of a line on:
https://brainly.com/question/16949303
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Answer:
They used the wrong formula, correct answer: -2.4
Step-by-step explanation:
The slope of a linear line, can be calculated using the formula: [tex]\frac{y_2-y_1}{x_2-x_1}[/tex]
Which can intuitively be understand, by realizing the definition of a slope is also generally defined as: [tex]\frac{\text{change in y}}{\text{change in x}}[/tex].
So the [tex]\text{change in y} = y_2 - y_1[/tex] and the [tex]\text{change in x} = x_2-x_1[/tex], and we just substitute these algebraic expressions to derive the slope formula.
Let's assign values to the x and y values as such:
[tex](x_1, y_1) = (2, -4)\\(x_2, y_2) = (-3, 8)[/tex]
Note: We could've assigned the values as such: [tex](x_1, y_1) = (-3, 8)\\(x_2, y_2) = (2, -4)[/tex]
and we would get the same slope, we just have to be consistent with how we plug in the x and y values.
from here we can substitute values into the equation to get:
[tex]m=\frac{8-(-4)}{-3-2}[/tex]
Now we can spot the error the student made. They used the wrong formula. The formula they used: [tex]\frac{x_2-y_2}{x_1-y_1}[/tex], as explained above, we can derive the slope formula by the common definition. This formula being used isn't finding the change in x and y, just the difference between the x and y coordinates.
If the student applied the formula correctly they would get the equation we got above.
We can further simplify the equation:
[tex]m=\frac{8-(-4)}{-3-2}[/tex]
To the following:
[tex]m=\frac{8+4}{-5}[/tex]
From here simplify the numerator further:
[tex]m=\frac{12}{-5}[/tex]
Which in decimal form is
[tex]m=-2.4[/tex]