Linear Equation Solver

Enter a, b and c for the equation ax + b = c. Sumzo isolates x step by step and checks the answer.

Whole numbers, decimals or fractions such as 3/4

Result

Enter values and press Calculate to see the result.

Formula

ax+b=c  ⇒  x=c−baax + b = c \;\Rightarrow\; x = \frac{c - b}{a}

Subtract b from both sides, then divide by a (when a ≠ 0).

How to use this calculator

  1. Rearrange your equation into the form ax + b = c (e.g. 5 − 2x = 9 has a = −2, b = 5, c = 9).
  2. Enter a, b and c and press Calculate.

Worked example

Solve 3x + 5 = 20

Subtract 5 from both sides: 3x = 15.

Divide by 3: x = 5. Check: 3 · 5 + 5 = 20.

Frequently asked questions

What if a = 0?

Then there is no x term. If b = c every number is a solution; otherwise there is no solution. Sumzo tells you which.

Can I solve equations with x on both sides?

Collect the x terms on one side first, or type the whole equation into Sumzo AI, which handles that automatically.

Learn more