A linear equation is a mathematical expression that represents a straight line when graphed on a coordinate plane. It typically has the form:
\[ ax + by = c \]
where:
- \( x \) and \( y \) are variables,
- \( a \), \( b \), and \( c \) are constants (with \( a \) and \( b \) not both zero).
In this equation:
- \( a \) and \( b \) determine the slope of the line,
- \( c \) indicates where the line intersects the axes.
Key Characteristics of Linear Equations:
- Degree: Linear equations are first-degree equations, meaning the highest exponent of the variables is 1.
- Graph: The graph of a linear equation is a straight line.
- Slope: The slope is a measure of how steep the line is and is given by the ratio \(-\frac{a}{b}\) when expressed in standard form.
- Intercepts: Linear equations can be used to find the x-intercept (where \( y = 0 \)) and y-intercept (where \( x = 0 \)).
Examples:
- Standard Form: \( 2x + 3y = 6 \)
- Slope-Intercept Form: \( y = mx + b \) where \( m \) is the slope and \( b \) is the y-intercept (e.g., \( y = 2x + 1 \)).
Applications:
Linear equations are widely used in various fields such as physics, economics, and statistics to model relationships between variables.