Linear equation solver
Enter the coefficients on both sides to get x. For an equation like ax + b = d, leave the right-hand x coefficient at 0.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter left x coefficient (a), left constant (b), right x coefficient (c) and right constant (d).
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Move x terms to one side and constants to the other: (a - c)x = d - b, so x = (d - b) / (a - c). If a = c there is no solution unless b = d, in which case every real number works.
Example
Inputs: Left x coefficient (a) = 5, Left constant (b) = -2, Right x coefficient (c) = 3, Right constant (d) = 6. Result: Value of x: 4.
Limits and caveats
- Solves one linear equation in one unknown; use the system solvers for two or three equations.
- Long decimals are rounded for display.
Questions about this tool
How do I solve 3x - 7 = 11?
Enter a = 3, b = -7, c = 0, d = 11. That gives 3x = 18, so x = 6.
When does the equation have no solution?
When the x coefficients on both sides match but the constants differ, like 2x + 1 = 2x + 5, which simplifies to 0 = 4.
Can I enter fractions?
Enter them as decimals: 1/2 as 0.5 and 1/4 as 0.25.