Enter your equation
Formula used
Inverse-operation principle: apply equal operations to both equation sides.
A + B = C becomes A = C - B.
A × B = C becomes A = C ÷ B.
A² = C becomes A = ±√C.
aˣ = C becomes x = ln(C) ÷ ln(a).
Ax² + Bx + C = 0 uses the quadratic formula.
How to use this calculator
- Enter one equation containing the target variable.
- Select the variable you want to isolate.
- Choose roots, angles, rounding, and assumptions.
- Submit the form and review every algebra step.
- Copy or export the completed result.
Example equations
| Original equation | Target | Rearranged form | Key restriction |
|---|---|---|---|
y = x + 5 | x | x = y - 5 | None |
y = 3x | x | x = y / 3 | 3 ≠ 0 |
y = (x + 2) / 4 | x | x = 4y - 2 | 4 ≠ 0 |
y = 10 / (x + 1) | x | x = 10 / y - 1 | y ≠ 0 |
y = x² + 1 | x | x = ±√(y - 1) | y ≥ 1 |
y = e^x | x | x = ln(y) | y > 0 |
y = sin(x) | x | x = asin(y) | -1 ≤ y ≤ 1 |
Frequently asked questions
What does making x the subject mean?
It means rearranging an equation until x stands alone. Other terms move using inverse operations. Both equation sides must remain balanced throughout.
Can the target variable appear on both sides?
Yes, linear and quadratic polynomial forms are supported. The calculator collects matching powers automatically. Unsupported nonlinear repeats produce a clear warning.
Why can an answer contain two roots?
Even powers often create positive and negative solutions. Squaring removes the original sign information. Check restrictions before selecting a branch.
Does the calculator support fractions?
Yes, it clears invertible fractional structures step-by-step. Denominators receive nonzero restrictions automatically. Nested unsupported forms may require manual simplification first.
Can it rearrange exponential equations?
Yes, logarithms isolate variables located in exponents. Positive-domain conditions are displayed with results. Invalid logarithmic bases are also restricted.
Are trigonometric answers complete general solutions?
The displayed answer uses the principal inverse function. Periodic families may create additional valid angles. Apply periodic rules for complete solution sets.
What input syntax should I use?
Use one equals sign and ordinary operators. Write powers with the caret symbol. Functions use brackets, such as sqrt(x).
When is a decimal approximation shown?
Decimals appear when the isolated expression contains only numbers. Symbolic parameters prevent direct numerical evaluation. Exact answers remain available in every mode.
How does the PDF export work?
The PDF button opens the browser print dialog. Choose the save-as-PDF printer option. Results and steps receive print-friendly formatting.