Data Table  -  A list of x-values and their corresponding y-values.

Negative Slope  -  y always decreases when x increases and y always increases when x decreases.

Ordered Pair  -  A pair of numbers in a specific order. For example, (3, 7) and (8, - 1) are ordered pairs. Two ordered pairs are equivalent if their first members are equal and their second members are equal. However, the order of the two numbers is important; (1, 2) is not equivalent to (2, 1).

Origin  -  The point (0, 0).

Parallel Lines  -  Two lines are parallel if they have the same slope. Parallel lines, when extended, do not intersect at any point.

Perpendicular Lines  -  Two lines are perpendicular if their slopes are opposite reciprocals of each other. Perpendicular lines intersect each other at right angles.

Positive Slope  -  y always increases when x increases, and y always decreases when x decreases.

Slope  -  Given two points (x₁, y₁) and (x₂, y₂) on a line, the slope of the line is equal to:

x-axis  -  The horizontal axis of a graph, with which the x-values are plotted.

x-coordinate  -  The number which corresponds to the value of x in an ordered pair.

x-intercept  -  The point at which the graph of a line crosses the x-axis. The point at which y = 0.

xy-graph  -  A two-dimensional way of representing points. x-values are plotted with the horizontal axis, and y-values are plotted with the vertical axis.

y-axis  -  The vertical axis of a graph, with which the y-values are plotted.

y-coordinate  -  The number which corresponds to the value of y in an ordered pair.

y-intercept  -  The point at which the graph of a line crosses the y-axis. The point at which x = 0.