Algebra calculator

Solve a × x + b = c and check the substitution.

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Coefficient a

Constant b

More inputs and assumptions

Right side c

Answer

…

For the linear equation a × x + b = c, subtract b from both sides, then divide by a: x = (c − b) ÷ a.

More results

Precision and calculation record

Decimal places in numeric results and text downloads

Rounding changes displayed numbers, not the calculation. Text, fractions, matrices and CSV schedules keep their own formatting. Automatic keeps up to 12 significant digits, with money shown to cents where applicable.

Saved scenario

Save the current answer, then change an input to compare. This clears when you leave.

Formula and assumptions

This solves one linear equation in one unknown, not arbitrary symbolic algebra. If a is zero, the equation is either always true or has no solution; no division is attempted.

Automatic precision shows numbers to 12 significant digits. Thousands separators such as 1,000 are accepted; use a dot for decimals.

Scratch calculator

Check another calculation

Use +, −, ×, ÷, parentheses and %. A percentage is divided by 100. This does not change the main tool.

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Updated 2026-09-26

Using Algebra calculator

For the linear equation a × x + b = c, subtract b from both sides, then divide by a: x = (c − b) ÷ a.

This solves one linear equation in one unknown, not arbitrary symbolic algebra. If a is zero, the equation is either always true or has no solution; no division is attempted.

Next: Midpoint calculator

A worked example

With coefficient a = 3, constant b = 5, right side c = 20, the solution is 5.

Next: Quadratic equation solver

Before you use the result

This solves one linear equation in one unknown, not arbitrary symbolic algebra. If a is zero, the equation is either always true or has no solution; no division is attempted.

Example results for coefficient a

These examples use Constant b: 5; Right side c: 20. They are reference calculations, not recommended settings.

Coefficient a	Solution
1.5	10
3	5
6	2.5

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