Equation Solver
Free online equation solver. Solve linear equations like 3x + 5 = 20 with full step-by-step working. Algebra made easy.
Linear Equation Solver
Enter an equation with one variable (x). Examples: 3x + 5 = 20 2x - 7 = x + 3 4x = 28
Comprehensive Guide & Practice
Master the mathematical principles, formulas, and step-by-step methods with worked examples and FAQs.
1. How to Solve Linear Equations
A linear equation is any equation where the variable appears to the first power only — no x², no x³. The goal is always to isolate the variable (usually x) on one side of the equation.
The golden rule: whatever you do to one side, you must do to the other side.
2. Step-by-Step Method
To solve 3x + 5 = 20:
- Subtract 5 from both sides: 3x = 15
- Divide both sides by 3: x = 5
- Verify: substitute back — 3(5) + 5 = 20 ✓
3. Equations with Variables on Both Sides
For 2x - 7 = x + 3: subtract x from both sides → x - 7 = 3 → add 7 to both sides → x = 10. Always collect all x terms on one side first.
4. Common Mistakes
- Forgetting to apply operations to BOTH sides of the equation.
- Sign errors when moving terms across the equals sign.
- Not verifying the answer by substituting back.
See also: Quadratic Equation Solver | Graphing Calculator | Linear Equations Guide | Algebra Basics