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algebra

Solving one-step equations

Use this page when you want the cleanest beginner route into equation solving before moving on to longer algebra questions.

Immediate answer

Start here if you want the short version before reading the full method.

  • A one-step equation needs only one inverse operation to isolate the variable.
  • Use the opposite operation of what is happening to the variable.
Quick explanation

What this topic means and what to look for first.

One-step equations are useful because they show the basic logic of solving without extra algebra clutter.

If this stage feels automatic, two-step and multi-step equations become much easier to manage.

Step-by-step method

One reliable route through the topic.

  1. 1Identify the single operation acting on the variable.
  2. 2Choose the inverse operation that undoes it.
  3. 3Apply that inverse operation to both sides.
  4. 4Check the result in the original equation.
Worked examples

See the method in action.

Example 1: addition

x + 7 = 12

  1. Subtract 7 from both sides.
  2. This gives x = 5.
  3. Check: 5 + 7 = 12.
Example 2: subtraction

x - 4 = 9

  1. Add 4 to both sides.
  2. This gives x = 13.
  3. Check: 13 - 4 = 9.
Example 3: multiplication and division

3x = 15 and x/5 = 3

  1. For 3x = 15, divide both sides by 3 to get x = 5.
  2. For x/5 = 3, multiply both sides by 5 to get x = 15.
  3. In both cases, the inverse operation isolates x immediately.
Common potential mistakes

Things that commonly send the method off track.

  • Using the wrong inverse operation.
  • Changing one side of the equation but not the other.
  • Rushing the arithmetic when the question looks too easy.
Check your answer

Use a short verification pass before moving on.

  • Substitute the final value back into the original equation.
  • Make sure the original left side really becomes the original right side after the substitution.
Practice questions

Try a few variations before switching to a calculator or solver tool.

  • x + 9 = 15
  • x - 6 = 10
  • 4x = 28
  • x/3 = 8
Follow-up access

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External revision resources

Extra algebra revision resources

If you want more printed algebra practice after this page, these broader searches are a sensible next step.

Amazon

Algebra workbook and revision book search

Useful if you want more equation, factorising, and worked-example practice in one printed source.

View Algebra workbook and revision book search

Amazon

GCSE algebra practice resources search

A wider GCSE-style search if you want more mixed algebra questions beyond one online guide.

View GCSE algebra practice resources search
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FAQ

Short answers worth checking.

What is a one-step equation?

It is an equation that needs only one inverse operation to isolate the variable.

What inverse operation should I use?

Use the opposite of the operation acting on the variable: subtract for addition, add for subtraction, divide for multiplication, and multiply for division.

How do I check my answer?

Substitute the value back into the original equation and see whether both sides match.

Next places to browse

Use the public site structure first, then switch into the solver tool only if you need a direct test.

CureMath uses artificial intelligence to suggest how a maths problem could potentially be solved. AI can make mistakes.

Check important answers independently before relying on them.