Linear Equations

The Basics

  • Simple definition: Mathematical equations where variables appear only to the first power, forming straight lines when graphed.
  • Core idea: Relationships with constant rates of change.
  • Think of it as: The simplest way to describe how two things are related.

What It Actually Means

Linear equations take the form y = mx + b, where m is the slope (rate of change) and b is the intercept (starting point). In economics, they appear in demand and supply curves (simplified), budget constraints, and many introductory models. They’re useful because they’re simple to solve and interpret.

Example

A simple demand function might be Q = 100 – 2P. For every 1 rupee increase in price, quantity demanded falls by 2 units. This linear relationship is easy to work with, even if real demand curves are often curved.

Why It Matters

Linear equations are the foundation of economic modeling. Students start here before moving to more complex functions. Understanding them is essential for grasping supply and demand, equilibrium, and basic forecasting.

See also

Slope • Intercept • Supply and Demand • Budget Constraint • Market Equilibrium

Read more about this with MASEconomics:

Linear Equations in Economics: Modeling Relationships and Market Equilibrium