Number Theory

Linear Congruence Solver

Solve linear congruences of the form ax ≡ b (mod m) quickly and easily with our interactive solver. Understand solutions and modular arithmetic concepts.

Solution

Solutions for $$ {${a}}x \equiv {${b}} \pmod{${m}} $$:

Understanding Linear Congruence

A linear congruence is a congruence relation of the form $$ax \equiv b \pmod{m}$$, where a, b, and m are integers, and x is a variable. Solving a linear congruence means finding all integer values of x that satisfy this relation.

Key Concepts:

  • Modulus (m): The integer m is called the modulus. The congruence is 'modulo m'.
  • Solutions: A linear congruence may have no solutions, one solution modulo m, or multiple solutions modulo m. The number of solutions depends on the greatest common divisor (gcd) of a and m.
  • GCD Condition: A solution exists if and only if the gcd(a, m) divides b. If it does, there are gcd(a, m) incongruent solutions modulo m.

Formula for Solutions: If a solution exists, and $$d = gcd(a, m)$$, then the solutions are given by: $$ x \equiv x_0 + k \cdot rac{m}{d} \pmod{m} $$ where $$x_0$$ is a particular solution, and $$k = 0, 1, 2, ..., d-1$$.

This tool helps you quickly find these solutions. Enter the coefficients a, b, and the modulus m to get the results.

Learn more about linear congruence at Wikipedia.

Frequently Asked Questions

What is the Linear Congruence Solver?
The Linear Congruence Solver is an online Number Theory calculator. You enter your values, and it returns the answer with the steps shown so you can follow along.
How accurate is the Linear Congruence Solver?
The solver uses a math engine that avoids the floating-point rounding errors you get from most hardware calculators. For typical homework and professional calculations, the results will match what you would get by hand.
Can I use the Linear Congruence Solver for professional Number Theory projects?
Yes. The math behind it is standard Number Theory, so the results are reliable for professional use. That said, always double-check that your inputs are in the right format before relying on the output.
Why use the Linear Congruence Solver instead of calculating by hand?
Manual calculation is slow and error-prone, especially with multiple steps. This tool does the arithmetic for you and shows each step, so you can catch mistakes before they carry forward.
How do I format my inputs for the Linear Congruence Solver?
Type your numbers into the input fields. Leave out units and symbols unless a field specifically asks for them. The solver handles the rest.