Algebra Calculator
Solve algebra equations step by step. Enter any linear or quadratic equation and get the solution with full working shown - ideal for homework help and learning algebra.
Solve Linear Equation: ax + b = c
Equation
2x + 5 = 15
Solution
x = 5
Step-by-Step Solution
Step 1: Start with equation
2x + 5 = 15
Step 2: Subtract 5 from both sides
2x = 15 - 5 = 10
Step 3: Divide both sides by 2
x = 10 / 2 = 5
Algebra Formulas
Linear Equation
ax + b = c, x = (c-b)/a
Distributive Property
a(b + c) = ab + ac
Combining Like Terms
ax + bx = (a+b)x
What Is an Algebra Calculator?
An algebra calculator is a tool that solves equations and simplifies expressions by handling the mechanical steps of algebra — isolating variables, combining like terms, and performing arithmetic — so you can focus on understanding the logic. This calculator covers two core algebraic operations: solving a linear equation of the form ax + b = c for x, and simplifying polynomial expressions by aggregating x-terms and constants.
Algebra is foundational to virtually every branch of mathematics and science. From calculating interest rates in finance to determining unknown quantities in physics, the ability to rearrange equations and simplify expressions is a skill used daily by students, engineers, and analysts. The calculator provides both the answer and a step-by-step breakdown, making it useful as a checking tool when working through homework problems or verifying manual derivations.
Unlike a generic solver that hides its workings, this tool shows you exactly which operations were applied — subtraction to isolate the x-term, division to solve for x — so you can trace the logic and learn the method in the process.
The Algebra Formula
Both modes rely on fundamental algebraic identities. The linear equation mode applies the standard isolation technique; the simplification mode uses the distributive property and the rule for combining like terms.
Linear Equation Solution
Where:
- a= Coefficient of x (must not be 0 for a unique solution)
- b= Constant added to the x-term on the left side
- c= Right-hand side constant of the equation
Understanding the Results
In linear equation mode, the calculator solves ax + b = c in three explicit steps:
| Step | Operation | Result |
|---|---|---|
| 1 | Start with the given equation | ax + b = c |
| 2 | Subtract b from both sides | ax = c - b |
| 3 | Divide both sides by a | x = (c - b) / a |
In simplification mode, the calculator extracts all terms containing x from your input expression and sums their coefficients, then separately sums all constant terms. The final output displays the aggregated coefficient of x and the total constant, giving you a clean simplified expression. This approach works for any linear-in-x expression with integer coefficients like 3x + 2x - 5 + 3.
How to Use This Calculator
Choose a mode and follow the steps below:
- Select the mode: Click Linear Equation to solve for x in ax + b = c, or Simplify Expression to combine like terms in a polynomial expression.
- For linear equations, enter the coefficients: Fill in the three input fields for a, b, and c. The equation display updates live. Valid values include positive and negative integers and decimals. If you set a = 0, the calculator reports no unique solution.
- For simplification, enter the expression: Type your algebraic expression in the text field using standard notation like "3x + 2x - 5 + 3". The calculator parses x-terms and constants and sums them separately.
- Review the solution: The calculator shows the solution in a highlighted display with the full step-by-step breakdown beneath it. For linear equations, you see each step with the arithmetic computed; for simplification, you see the separate coefficient and constant totals.
Real-World Applications
Linear equations of the form ax + b = c model a vast range of real-world scenarios. In personal finance, if you know the monthly payment on a loan, the interest rate, and the total amount, you can rearrange the equation to solve for the unknown — whether that's the principal, the term length, or the monthly contribution. In business operations, break-even analysis uses linear equations to find the sales volume at which revenue equals costs.
Expression simplification is essential in computer algebra systems and symbolic computation, where reducing an expression to its simplest form makes subsequent calculations faster and less error-prone. In engineering spreadsheets, long formulas with repeated variables can be simplified by hand before entering them as cell formulas, reducing both clutter and computation time. Even in basic physics, combining like terms lets you reduce a multi-variable equation to a clean, solvable form.
Worked Examples
Solving a Basic Linear Equation
Problem:
Solve the equation 2x + 5 = 15 for x.
Solution Steps:
- 1Enter a = 2, b = 5, c = 15 in linear equation mode.
- 2Step 1: Start with 2x + 5 = 15.
- 3Step 2: Subtract 5 from both sides → 2x = 10.
- 4Step 3: Divide both sides by 2 → x = 5.
Result:
x = 5. Plugging back in: 2(5) + 5 = 10 + 5 = 15, which matches the right-hand side.
Solving a Linear Equation with Negative Coefficients
Problem:
Solve 3x - 4 = 11.
Solution Steps:
- 1Enter a = 3, b = -4, c = 11 in linear equation mode.
- 2Step 1: Start with 3x - 4 = 11, which is equivalent to 3x + (-4) = 11.
- 3Step 2: Subtract (-4), i.e., add 4 to both sides → 3x = 15.
- 4Step 3: Divide both sides by 3 → x = 5.
Result:
x = 5. Check: 3(5) - 4 = 15 - 4 = 11. Correct.
Simplifying a Polynomial Expression
Problem:
Simplify the expression 3x + 2x - 5 + 3.
Solution Steps:
- 1Switch to Simplify Expression mode and enter '3x + 2x - 5 + 3'.
- 2Step 1: Identify x-terms: 3x and 2x → combined coefficient = 3 + 2 = 5.
- 3Step 2: Identify constant terms: -5 and 3 → combined constant = -5 + 3 = -2.
- 4Step 3: Assemble: 5x - 2.
Result:
5x - 2. The expression is reduced to its simplest linear form.
Tips & Best Practices
- ✓Always double-check the signs on b and c — a sign error is the most common mistake in linear equation solving.
- ✓If the expression simplification gives an unexpected result, check that you typed the expression exactly as '3x + 2x - 5 + 3' with spaces around operators.
- ✓Use the step-by-step breakdown as a teaching tool — each step corresponds to exactly one algebraic operation.
- ✓When b is negative, the calculator treats it as ax + (-|b|) = c, and the subtraction step becomes addition in practice.
- ✓You can use decimal inputs like 2.5 and -1.75 — the calculator handles them with floating-point precision.
- ✓For equations with variables on both sides, rearrange manually to put everything in ax + b = c form first.
Frequently Asked Questions
Sources & References
Last updated: 2026-06-06
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Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
Formula Source: Handbook of Mathematical Functions
by Abramowitz & Stegun