Final answer:
The incorrect expressions for slope are Δx/Δy, because it incorrectly reverses the numerator and denominator, and 'rise' by itself, as it omits 'run'.
Step-by-step explanation:
In mathematics, the slope of a line measures how steep the line is. It is calculated as the rise (change in y) divided by the run (change in x) between two points on the line. The correct expressions for slope include the ratio of the differences in y-values to the differences in x-values, Δy/Δx or (y2-y1)/(x2-x1), and the description of slope as the change in the dependent variable relative to change in the independent variable.
Option A, Δx/Δy, is incorrect because it reverses the positions of Δx and Δy, implying that slope is calculated by dividing the change in the independent variable by the change in the dependent variable, which is not standard convention. Lastly, while 'rise' is related to slope as it refers to the vertical change, the word alone is not a complete expression of slope as it does not include 'run'.