Equation Solver
Solve linear and quadratic equations quickly. Supports real and complex roots for quadratic equations.
Result
Equation
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Type
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Discriminant
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Roots
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About Equation Solver
This tool solves linear and quadratic equations in standard algebraic form. Linear equations have one variable term, while quadratic equations include a squared term and may produce two real or two complex roots.
Supported Forms
- Linear:
ax + b = 0— one real solution - Quadratic:
ax² + bx + c = 0— up to two solutions (real or complex)
How to Use
- Choose Linear or Quadratic from the equation type selector.
- Enter the coefficients a, b, and (for quadratic) c.
- Click Solve — the solution(s) and step-by-step working appear below.
How It Works
For linear equations: x = −b / a.
For quadratic equations: the discriminant Δ = b² − 4ac determines the nature of roots. If Δ > 0, two distinct real roots. If Δ = 0, one repeated root. If Δ < 0, two complex conjugate roots.
Example
Solve 2x² − 4x − 6 = 0: a=2, b=−4, c=−6. Discriminant = 16 + 48 = 64. Roots: x = (4 ± 8) / 4 → x = 3 and x = −1.
Frequently Asked Questions
When the discriminant is negative, the quadratic has no real solutions. The roots are complex numbers of the form a ± bi, where i is the imaginary unit (√−1). The tool displays these clearly.
Yes. Enter decimal values for any coefficient (e.g. a=1.5, b=−2.3, c=0.7). The solver handles both integer and floating-point inputs.
If a=0, the equation becomes linear (not quadratic). Use the Linear equation type instead, or enter a non-zero value for a.
Not currently. The solver supports linear (degree 1) and quadratic (degree 2) equations only. For higher-degree polynomials, consider using a computer algebra system.