Algebra Calculator
Algebra calculator works out Solutions and Solution from Equation (or expression to simplify), Solve for and Numeric search from. The default figures on this page give solution of 2; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
4 steps
- Bring everything to one side: 2x - 4 = 0
- Add 4 from both sides: 2x = 4
- Divide both sides by 2: x = 2
- Check x = 2: substituting back leaves left - right = 0.
Solutionstable
Check by substitutiontable
Its 6 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
3 sources
What the algebra calculator calculates
Solves an equation in one unknown, showing the working: exact rational solutions for linear, quadratic and higher polynomial equations, inverse operations for equations where the unknown appears once, and a labelled numeric search otherwise.
How to use this algebra calculator
Enter Equation (or expression to simplify), Solve for, Numeric search from and Numeric search to. Solutions updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Solutions, Solution and Number of real solutions.
The method follows OpenStax, Elementary Algebra 2e, chapters 2 and 9: solving linear equations and quadratic equations, OpenStax, College Algebra 2e, section 5.5: Zeros of polynomial functions (rational zero theorem, factor theorem) and W. H. Press et al., Numerical Recipes, 3rd edition, section 9.1: bracketing and bisection.
Linear: 2x + 3 = 7 example
With Equation (or expression to simplify): 2x + 3 = 7, Solve for: x, the calculator returns Solution: 2, Number of real solutions: 1, Kind of equation: linear. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Solutions, Solution and Number of real solutions. The inputs you can vary are Equation (or expression to simplify), Solve for, Numeric search from and Numeric search to.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
What information do I need for the algebra calculator?
You need Equation (or expression to simplify), Solve for, Numeric search from and Numeric search to. The page opens with default figures that give solution of 2, so you can see the scale before entering your own.
What does this algebra calculator show?
It shows Solutions, Solution, Number of real solutions, Kind of equation, Standard form, Simplified expression, Factored form and Complex solutions, with the working and any warnings for your entries.
Can I check how the algebra calculator result was calculated?
Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.