Algebra Calculator

Solve quadratic equations ax2 + bx + c = 0

Quadratic Equation Solver

Find roots of ax2 + bx + c = 0

Formula
x = (-b +/- sqrt(b2 - 4ac)) / 2a

What is an Algebra Calculator?

An Algebra Calculator is a math tool that helps you work with algebraic expressions and equations quickly and accurately. Algebra is the branch of mathematics that uses variables (like x, y, or z) to represent unknown values and uses rules to simplify expressions, solve equations, factor polynomials, and expand or rearrange terms.

Instead of doing long manual steps—like combining like terms, distributing parentheses, or solving for a variable—an algebra calculator can perform these operations instantly. This is especially helpful for checking homework, verifying steps in a math problem, or exploring "what-if" scenarios by changing values.

Algebra calculators are commonly used in middle school and high school math (pre-algebra, algebra 1/2), as well as in college courses like calculus, physics, chemistry, economics, and engineering—anywhere equations and formulas need to be simplified or solved.

How to Use This Algebra Calculator

  1. Enter your expression or equation -- Example expressions: 3x + 2x - 7 or 2(x + 4) - 3x. Example equations: 2x + 5 = 17.
  2. Choose the operation (if applicable) -- such as Simplify, Solve, Factor, Expand, or Evaluate.
  3. Select the variable (if applicable) -- for example, solve for x.
  4. Click "Calculate" -- the calculator will produce the simplified form or solution.
  5. Review the result -- some calculators also show steps; if shown, use them to learn the process.

Tips:

  • Use parentheses to clearly group terms: 2(x + 3)
  • Use ^ for exponents if supported: x^2
  • If you get an unexpected result, double-check signs and parentheses (most mistakes come from missing parentheses or negative signs)

Algebra Formulas

Combining Like Terms

Like terms have the same variable part (same variables raised to the same powers):

  • 3x + 2x = 5x
  • 7a² − 4a² = 3a²

Distributive Property

Rule: a(b + c) = ab + ac

Example: 2(x + 5) = 2x + 10

Solving a Linear Equation

General form: ax + b = c

Solve for x: x = (c − b) / a

Isolate x by subtracting b, then dividing by a

Factoring a Quadratic

Form: x² + bx + c

Find two numbers that multiply to c and add to b:

x² + bx + c = (x + m)(x + n)

Quadratic Formula (Solving ax² + bx + c = 0)

x = (−b ± √(b² − 4ac)) / 2a

The expression b² − 4ac is the discriminant, which determines the number and type of solutions:

  • Discriminant > 0: two distinct real roots
  • Discriminant = 0: one repeated real root
  • Discriminant < 0: two complex (imaginary) roots

Example Calculations

Example 1: Simplify an expression

Expression: 3x + 2x − 7

Step: Combine like terms: 3x + 2x = 5x

Answer: 5x − 7

Example 2: Expand using distribution

Expression: 2(x + 4) − 3x

Step 1: Distribute: 2(x + 4) = 2x + 8

Step 2: Subtract 3x: (2x + 8) − 3x = −x + 8

Answer: 8 − x

Example 3: Solve a linear equation

Equation: 2x + 5 = 17

Step 1: Subtract 5 from both sides: 2x = 12

Step 2: Divide by 2: x = 6

Answer: x = 6

Example 4: Factor a quadratic

Expression: x² + 5x + 6

Step: Find two numbers that multiply to 6 and add to 5 → 2 and 3

Answer: (x + 2)(x + 3)

Frequently Asked Questions

What is a variable in algebra?

A variable is a symbol (like x or y) that represents an unknown or changeable value. For example, in 2x + 3, the value of x can vary.

What does it mean to "simplify" an expression?

Simplifying means rewriting an expression in a cleaner form by combining like terms, reducing fractions, and removing unnecessary parentheses—without changing its value.

What's the difference between an expression and an equation?

An expression does not have an equals sign (example: 3x + 2). An equation includes an equals sign and states two things are equal (example: 3x + 2 = 11).

Why do I need parentheses?

Parentheses show grouping and control the order of operations. For example, 2(x + 3) is different from 2x + 3.

Can an algebra calculator solve any equation?

Many can solve common types (linear, some quadratics, basic systems), but very complex equations may have restrictions depending on the tool. If your equation doesn't solve, try simplifying it first or confirm the calculator supports that equation type.

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