A student was trying to use the points (1, –19) and (–2, –7) to write an equation of a line in slope-intercept form.
Find and explain the error in the work below.
The error in the work below is that the student incorrectly calculated the slope of the line.
To find the slope of a line passing through two points (x1, y1) and (x2, y2), we use the formula:
slope = (y2 - y1) / (x2 - x1)
In this case, the student calculated the slope as:
slope = (-7 - (-19)) / (-2 - 1) = 12 / -3 = -4
However, the correct calculation should be:
slope = (-7 - (-19)) / (-2 - 1) = 12 / -3 = -4
So the error is in the calculation of the slope. The rest of the work appears to be correct.