Equation Solver
Solving 3x + 7 = 22 takes two lines; x^2 - 5x + 6 = 0 is one step further. Enter the coefficients of a linear or quadratic equation and this solver returns the solution, or the two roots together with the discriminant. When a quadratic has no real roots, the complex conjugate pair is shown as a + bi.
How to solve an equation
-
1
Choose the equation type
Pick linear (`ax + b = 0`) or quadratic (`ax^2 + bx + c = 0`).
-
2
Enter the coefficients
Type the values of a, b and c. The result updates as you type.
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3
Read the solutions
A linear equation has one solution. A quadratic has two real roots, or a complex conjugate pair, and the discriminant is shown as well.
What the solver handles
| Equation form | Method |
|---|---|
Linear ax + b = 0 |
Solve x = -b/a |
Quadratic ax^2 + bx + c = 0 |
Quadratic formula with the discriminant D = b^2 - 4ac |
Worked example
x^2 - 5x + 6 = 0
Step 1: Identify a=1, b=-5, c=6. Step 2: Compute the discriminant: D = 25 - 24 = 1. Step 3: D > 0 means two real roots. Step 4: Apply the quadratic formula: x = (5 +/- 1) / 2. Step 5: Roots: x = 3 and x = 2. Step 6: Verify: 9 - 15 + 6 = 0 ✓ and 4 - 10 + 6 = 0 ✓.
Linear equations
A linear equation ax + b = 0 has one root: x = -b/a. If a = 0 and b = 0, every value of x satisfies the equation; if a = 0 and b is not zero, there is no solution. The solver reports both cases.
Complex roots
When the discriminant is negative, the quadratic has no real roots. The solver shows the complex conjugate pair as real + imagi and real - imagi. For example, x^2 + 4 = 0 gives the roots 0 + 2i and 0 - 2i.
What the solver does not do
This solver handles one linear or quadratic equation with numeric coefficients. It does not parse typed-in equations, solve cubic or higher-degree polynomials, handle equations with absolute values or roots, or solve systems of equations. Use a dedicated tool for those cases.
Common mistakes
- Sign errors. The most common cause of unexpected roots. Check every coefficient, especially b in
x^2 - 5x + 6 = 0:-5is not the same as5. - Expecting real roots when the discriminant is negative. A negative
Dmeans the roots are complex, not that you entered the wrong numbers. VerifyD = b^2 - 4acwhen in doubt. - Forgetting the
a = 0case. Witha = 0the equation becomes linear; the solver handles it automatically.
Frequently Asked Questions
No. This solver works on one linear or quadratic equation at a time. For simultaneous equations, use a dedicated linear system solver.
No. Only linear and quadratic equations are supported. Cubic and higher-degree polynomials, as well as equations like x = cos(x), are outside the scope of this tool.
A simple-looking quadratic like x^2 + 1 = 0 has no real roots, only the complex pair 0 + 1i and 0 - 1i. If your problem expects real answers, re-check the signs of the coefficients; if complex roots are meaningful in your context (physics, engineering), use them.
No. The coefficients are used to compute the result and are not stored or uploaded. In the step-by-step view they travel inside the page link when you move between steps; nothing is kept on our servers.
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Tool available in other languages
- حلّال المعادلات [AR]
- Solucionador de ecuaciones [ES]
- 方程求解器 [ZH]
- Trình giải phương trình [VI]
- 方程式ソルバー [JA]
- Résolveur d'équations [FR]
- Ekvationslösare [SV]
- Resolvedor de Equações [PT]
- ตัวแก้สมการ [TH]
- Vergelijkingsoplosser [NL]
- 방정식 풀이기 [KO]
- Solver równań [PL]
- Denklem Çözücü [TR]
- Gleichungslöser [DE]
- Penyelesai Persamaan [ID]
- Risolutore di equazioni [IT]
- Решение уравнений [RU]