Solve for x Calculator
Enter a linear equation with an equals sign, and this tool will solve for x.
What does “solve for x” mean?
When you solve for x, you are finding the value that makes an equation true. In algebra, x is an unknown number. The equation gives you clues about how that unknown is related to known numbers.
For example, in 2x + 5 = 17, solving for x means finding the number that, when doubled and then increased by 5, equals 17. The answer is x = 6.
How to use this calculator
1) Enter your equation
Type your equation in one line with an equals sign. You can use parentheses and basic arithmetic.
- Good:
2x + 5 = 17 - Good:
3(x - 2) = x + 10 - Good:
x/4 + 7 = 10
2) Click “Solve for x”
The calculator simplifies both sides, moves all x-terms to one side, constants to the other, and computes the value of x.
3) Read the result
You may get one of three outcomes:
- One solution: a single value for x
- No solution: contradiction (like 4 = 9)
- Infinitely many solutions: identity (like 2x + 3 = 2x + 3)
Quick algebra method (manual solving)
If you want to solve by hand, this simple process works for most linear equations:
- Distribute and simplify each side.
- Move all x terms to one side.
- Move constants to the other side.
- Divide by the coefficient of x.
Example: 5x - 9 = 2x + 12
Subtract 2x from both sides: 3x - 9 = 12
Add 9 to both sides: 3x = 21
Divide by 3: x = 7
Common mistakes to avoid
- Forgetting signs: moving a term changes its sign.
- Not distributing correctly: in
3(x - 2), both terms multiply by 3. - Skipping parentheses: they control operation order.
- Mixing unlike terms: combine x terms with x terms, constants with constants.
FAQ
Can this solve quadratic equations?
No. This page is focused on linear equations (first degree in x). If your equation includes x² or other nonlinear behavior, use a quadratic or symbolic solver.
What if the equation has x on both sides?
That is fully supported. The calculator automatically consolidates terms and determines whether there is one answer, no answer, or infinitely many answers.
Can I use decimals and fractions?
Yes. Decimals like 0.5x + 1.2 = 4.7 and fractions like x/3 + 2 = 5 are accepted.
Final tip
A good habit is to verify your answer by substituting x back into the original equation. If both sides are equal, your solution is correct.