Linear Equation Calculator

Solve a linear equation ax + b = 0 for x.

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Enter the coefficients a and b to solve ax + b = 0 for x.

Your result

-2

x

AI explanation

Formula

ax + b = 0, so x = −b ÷ a

Worked example

2x + 4 = 0

Worked example: 2x + 4 = 0
FieldValue
Coefficient a2
Coefficient b4
x-2

Assumptions

  • Coefficient a cannot be 0, since then the equation wouldn't be linear in x.

Frequently asked questions

How do you solve a linear equation?

Isolate x by moving all other terms to the other side — for ax + b = 0, subtract b from both sides and divide by a, giving x = -b/a.

What if my equation isn't in the form ax + b = 0?

Rearrange it first — for example, 3x = 9 - x becomes 4x - 9 = 0, so enter a=4, b=-9.

Is there a version for two equations with two unknowns?

Yes — see the System of Equations Calculator for that.

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