Key Terms

Ordered Pair: An ordered pair is a pair of numbers written in parentheses in which the order of the numbers is important.  

Origin: When two number lines intersect at a right angle, the origin is the common point 0.

X-axis: The horizontal number line in a rectangular coordinate system. 

Y-axis: The vertical number line in a rectangular coordinate system.

Rectangular (Cartesian) Coordinate system: Two number lines that intersect at a right angle at their 0 points form a rectangular coordinate system, also called the Cartesian coordinate system.

Plot: To plot an ordered pair is to locate it on a rectangular coordinate system.

Components: The two numbers in an ordered pair

Coordinate: Each number in an ordered pair represents a coordinate of the corresponding point

Quadrant: A quadrant is one of the four regions in the plane determined by a rectangular coordinate system

Graph of an equation: The graph of an equation is the set of points corresponding to all ordered pairs that satisfy the equation

First degree equation: A first degree equation has no term with a variable to a power greater than one.
Linear equation in two variables: A first degree equation with two variables is a linear equation in two variables


X-intercept: Point where a line intersects the x-axis


Y-intercept: Point where a line intersects the y-axis

Rise: vertical change between two points on the line


Run: Horizontal change between two points on the line


Slope: Ratio of the change in y compared to the change in x along a line is the slope of the line