Assessment and Learning in Knowledge Spaces (ALEKS) Practice Exam

What condition indicates a line with a slope of zero?

1. It varies in y but remains constant in x

2. It varies in x but remains constant in y

3. It is a vertical line

4. It does not change in either direction

The correct answer is: It varies in y but remains constant in x

A line with a slope of zero indicates that there is no change in the y-value as the x-value changes. This is characteristic of a horizontal line. When a line varies in y but remains constant in x, it means that for any given value of x, the y-value stays the same, which is the definition of a horizontal line. In other words, if you were to plot this relationship on a graph, you would see that moving along the x-axis (changing x) does not affect the position on the y-axis—resulting in a flat line across the graph. The other options describe different types of relationships or line orientations that do not represent a slope of zero. For instance, a vertical line has an undefined slope due to the x-value remaining constant while y varies, whereas the choice indicating no change in either direction depicts a point rather than a line and does not adequately represent a line with a slope of zero.