Simultaneous Equations Solver - Solve 2×2 & 3×3 Systems

Solve systems of 2 or 3 linear equations with multiple variables. Get step-by-step solutions using elimination, substitution, or matrix methods.

Updated: November 2025 • Free Tool

System of Equations

Equation 1: ax + by = e
Equation 2: cx + dy = f

Solution

Variables
x = 0, y = 0
Determinant 0
Solution Type Unique
Method Used Elimination

What is a Simultaneous Equations Solver?

A Simultaneous Equations Solver is a mathematical tool that finds the values of multiple variables that satisfy all given equations at the same time. It solves systems of linear equations with 2 or 3 unknowns.

This calculator works for:

  • 2×2 Systems - Two equations with two variables (x and y)
  • 3×3 Systems - Three equations with three variables (x, y, and z)
  • Multiple Methods - Elimination, substitution, and matrix approaches

To solve quadratic equations, try our Quadratic Equation Solver with step-by-step solutions.

For completing the square method, check our Completing the Square Calculator to convert to vertex form.

To calculate slope and intercepts, use our Slope & Intercept Calculator for linear equations.

How the Solver Works

For 2×2 systems, the calculation uses Cramer's Rule:

x = (ef - bd) / (ad - bc)
y = (ae - cf) / (ad - bc)

Where:

  • Determinant (D) = ad - bc
  • D_x = ef - bd
  • D_y = ae - cf

Key Concepts Explained

Determinant

A number calculated from coefficients that determines if a unique solution exists.

Elimination Method

Adding or subtracting equations to eliminate one variable at a time.

How to Use This Calculator

1

Choose System Size

Select 2×2 or 3×3 system

2

Enter Coefficients

Input all equation coefficients

3

Click Solve

Get solutions and steps

Benefits of Using This Calculator

  • Instant Solutions: Get answers for complex systems in seconds.
  • Step-by-Step Process: Understand the solution method with detailed steps.
  • Multiple Systems: Solve both 2×2 and 3×3 systems with one tool.

Factors That Affect Your Solution

1. Determinant Value

If determinant = 0, the system may have no solution or infinite solutions.

2. Equation Dependency

If equations are multiples of each other, solutions may be infinite.

Simultaneous Equations Solver - Free online calculator to solve 2×2 and 3×3 systems of linear equations with step-by-step solutions
Professional simultaneous equations solver interface for solving systems of linear equations. Features include 2×2 and 3×3 system support, step-by-step solutions, and multiple solution methods.

Frequently Asked Questions (FAQ)

Q: What are simultaneous equations?

A: Simultaneous equations are a set of two or more equations with multiple variables that are solved together to find values that satisfy all equations at the same time.

Q: What methods can be used to solve simultaneous equations?

A: Common methods include elimination (adding or subtracting equations), substitution (solving for one variable and substituting), and matrix methods (using Cramer's rule or Gaussian elimination).

Q: Can simultaneous equations have no solution?

A: Yes, if the equations represent parallel lines (for 2×2) or parallel planes (for 3×3), they will have no solution. This occurs when the equations are inconsistent.

Q: What is Cramer's Rule?

A: Cramer's Rule is a method for solving systems of linear equations using determinants. It provides explicit formulas for each variable using ratios of determinants.

Q: When do simultaneous equations have infinite solutions?

A: Simultaneous equations have infinite solutions when all equations represent the same line or plane. This happens when the equations are dependent (one is a multiple of another).