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Solve multi-step equations

About 9 minutes · 3 reading + 6 practice and checks
Time includes reading, practice, and questions. Extra videos or further study are optional.
See this course’s project requirements

A checked algebra notebook that models four situations, solves equations and inequalities, and tests solutions against the original conditions.

Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.

What to include

  • Include four clearly defined quantity models with units.
  • Show balanced transformations and distribution in at least one model.
  • State a permitted inequality set and check its boundary.
  • Check each final value in its original relationship.
  • Add all six changed-case responses and explain one infeasible whole-number arrangement.

Review and revise

Use these criteria to check your work and choose what to improve.

  • Method: applies the course-specific rules to the supplied cases with visible intermediate work.
  • Accuracy: results agree with the stated facts, units, boundaries and independent checks.
  • Reasoning: explains why the result follows and identifies a limitation or unresolved question.
  • Transfer: completes changed cases and revises the final project when a relevant assumption changes.
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Before you begin

The idea in everyday life

Original case: 5x − 8 = 27; x is a number of identical model tokens.

The idea

Undo operations in reverse order while preserving equality. Keep each intermediate equation visible, and verify the proposed value in the original equation rather than only in the last line.

Follow along

Solve multi-step equations — worked practice

Undo operations in reverse order while preserving equality. Keep each intermediate equation visible, and verify the proposed value in the original equation rather than only in the last line.

Original case: 5x − 8 = 27; x is a number of identical model tokens.

Case information

Paste at A1.

ARecordBGiven
Original caseOriginal case: 5x − 8 = 27; x is a number of identical model tokens.

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  1. 1. 1. Identify operations

    Describe what happens to x before the result is 27.

    You should see: x is multiplied by five, then eight is subtracted.

  2. 2. 2. Undo subtraction

    Add eight to both sides.

    You should see: 5x = 35.

  3. 3. 3. Undo multiplication

    Divide both sides by five.

    You should see: x = 7.

  4. 4. 4. Verify

    Evaluate the original left side at seven.

    You should see: 5 × 7 − 8 = 27; the equation is satisfied.

Now change one thing

Change the right side to 42: 5x − 8 = 42.

Your work

What to finish

A multi-step equation solution showing each inverse operation.

Common mistake

Watch for this

The original equation tests whether a transformation error occurred.

How can I tell I understand it?

Solve a changed two-operation equation without checking only the final line.

Try 3 questions

Quick knowledge check

Answer all 3 questions. Get at least 2 right and the lesson completes automatically.

Not yet passed

You’ll get an explanation for each answer. Signed in? Your results save to your account.

1Solve 4n − 3 = 25.
2Which is the correct first transformed line for 5x−8=27?
3A learner obtains x=7 and checks only 7=7. What useful check is missing?
0 of 3 answeredApply the lesson to a short question, then review the explanation.
3
Finish this lesson

Pass the check. We’ll save the progress.

Answer all 3 questions above and get at least 2 right. You can review the explanations and try again.

Go to the knowledge check
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Sources and further reading

Explore the references behind this lesson.

OpenStax: linear-equation strategy
Source & access notes · checked 2026-10-01

Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.

Access: Official page retrieved with the web reader on 2026-10-01; interactive tools and videos were not certified by retrieval.

Reuse: Original fictional teaching cases, calculations, questions and examples; link and short factual paraphrase only. No copied source exercises or illustrations.

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