Linear System Solver Ax = b
A system of linear equations Ax = b can be solved by Gaussian elimination, and this calculator determines whether the system has a unique, infinite, or no solution. Detects unique, infinite, or no solution. Shows augmented matrix RREF and back-substitution with full steps.
System of Linear Equations Ax = b
Enter coefficient matrix A and constants b
Solving Systems of Linear Equations
A system of linear equations is a set of equations sharing the same variables, like 2x + y = 5 and x - y = 1. Writing this as Ax = b lets us solve many equations at once using matrix methods, which is far faster than solving them one at a time by substitution.
Types of Solutions
- Unique solution: rank(A) = rank([A|b]) = n. One exact solution vector x.
- Infinite solutions: rank(A) = rank([A|b]) < n. Free variables exist.
- No solution: rank(A) < rank([A|b]). System is inconsistent.
Solution Method
This solver uses augmented matrix RREF (Gauss-Jordan elimination), which systematically reduces [A|b] to [I|x] for unique solutions or identifies pivot/free variables for other cases.
Worked Example
For the system 2x + y = 5 and x - y = 1: written in matrix form, A = [[2,1],[1,-1]] and b = [5,1]. Solving gives x = 2 and y = 1 — you can check this works by substituting back into both original equations.
Applications
- Circuit analysis in electrical engineering
- Balancing chemical equations
- Finding intersection points in economics and optimization problems
Frequently Asked Questions
Related Calculators
- Inverse Matrix Calculator — one method: x = A⁻¹b
- RREF Calculator — another method: row reduce the augmented matrix
- LU Decomposition Calculator — efficient for solving the same system repeatedly