A linear function is a mathematical relationship between two variables that can be represented by a straight line on a graph. It is typically expressed in the form y = mx + b, where m is the slope of the line, indicating its steepness, and b is the y-intercept, which is the point where the line crosses the y-axis. Linear functions show a constant rate of change, meaning that for every unit increase in x, the value of y changes by a fixed amount. Linear functions are widely used in various fields, including economics, physics, and engineering, to model real-world situations. For example, they can represent relationships like distance over time or cost as a function of quantity. Understanding linear functions is essential for solving problems involving proportional relationships and making predictions based on trends.