Two-Step Equations

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x =

Enter a, b, and c — toggle ＋/− for the sign of b. Coefficient a cannot be 0.

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Solution

Enter values above and press Solve Equation to see the answer and steps.

Solution

x = —

Balance Scale

ax + b

Whatever you do to one side, do to the other.

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Coefficient a

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Constant b

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x =

What Is a Two-Step Equation?

ax + b = c → x = (c − b) / a

A two-step equation is one where you need exactly two inverse operations to isolate the variable x. The standard form is ax + b = c, where a is the coefficient of x, b is a constant added or subtracted, and c is the value on the right side.

Step 1 — Undo addition or subtraction: Add or subtract b from both sides to eliminate the constant term, leaving ax = c − b.

Step 2 — Undo multiplication: Divide both sides by a to find x = (c − b) / a.

We undo operations in reverse order — addition/subtraction before multiplication/division — because we are working backwards through the order of operations.

Think of the equation as a balance scale: any operation performed on one side must also be performed on the other to keep it balanced.

Work Backwards from PEMDAS

When an equation is built, operations are applied to x in PEMDAS order — multiply first, then add. To undo them, reverse the order:

First undo addition or subtraction (the outermost operation).
Then undo multiplication or division (the inner operation).
The variable x is now isolated — that is your answer.
Always verify: plug x back into the original equation to confirm both sides are equal.

Undo addition/subtraction first, then multiplication/division — the opposite of PEMDAS.

Still tricky to see the steps?