Linear Equation
See It in Action
Two examples of the idea done right—and one common look-alike that is not right.
EXAMPLE
EXAMPLE
NON-EXAMPLE
Definition
Linear equations are mathematical statements that express a relationship between two variables in the form of a straight line when graphed. They can be represented in several ways, with the most common form being:
y = mx + b
where:
y is the dependent variable,
x is the independent variable,
m is the slope of the line (indicating how steep it is), and
b is the y-intercept (the point where the line crosses the y-axis).
Linear equations have the following characteristics:
Degree: The highest exponent of the variable is 1. It does not include squared or higher degree terms.
Graph: The graph of a linear equation is always a straight line.
For example, the equation 2x + 3y = 6 is a linear equation in two variables. You can rearrange it into the slope-intercept form y = -2/3x + 2 to find its slope and y-intercept.
Linear equations can be written in 3 main forms.
Standard Form: Ax + By = C
Slope-Intercept Form: y = mx + b
Point-Slope Form: y - y1 = m(x - x1)