Linear Equation Calculator
Solve equations like 3x + 5 = 20 with every step shown.
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How to use this calculator
Type your equation with one unknown letter. The answer, every step and a check appear straight away.
How it's calculated
Collect all the unknown terms on one side and the numbers on the other, then divide by the number in front of the letter: if ax + b = 0 then x = −b / a.
Worked example
3x + 5 = 20. Subtract 5 from both sides to get 3x = 15, then divide by 3 so x = 5. Check: 3 × 5 + 5 = 20 ✓
Frequently asked questions
What if both sides cancel out?
If the letters cancel and the numbers match, every value works. If the numbers do not match, there is no solution. The calculator tells you which one it is.
Can I use fractions?
Yes. Type them like x/3 + 2 = 5 or 1/2x = 4.
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Last updated October 2026. Results are for learning and guidance; always check important work. Calculations run in your browser and are not stored.