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Handle brackets and like terms

About 10 minutes · 3 reading + 7 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: 2(x + 3) + x = 21.

The idea

Distribution multiplies every term inside a bracket. Like terms have the same variable part; their coefficients may be combined. Do not combine a variable term with a constant as if they measured the same thing.

Follow along

Handle brackets and like terms — worked practice

Distribution multiplies every term inside a bracket. Like terms have the same variable part; their coefficients may be combined. Do not combine a variable term with a constant as if they measured the same thing.

Original case: 2(x + 3) + x = 21.

Case information

Paste at A1.

ARecordBGiven
Original caseOriginal case: 2(x + 3) + x = 21.

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  1. 1. 1. Distribute

    Multiply both bracket terms by two.

    You should see: 2x + 6 + x = 21.

  2. 2. 2. Combine like terms

    Add the coefficients of x while leaving six separate.

    You should see: 3x + 6 = 21.

  3. 3. 3. Solve

    Subtract six, then divide by three.

    You should see: 3x = 15; x = 5.

  4. 4. 4. Check distribution

    Substitute five into the bracketed original expression.

    You should see: 2(5+3)+5 = 16+5 = 21.

Now change one thing

Solve 3(x + 2) + x = 30.

Your work

What to finish

A bracket expansion, simplified equation and checked solution.

Common mistake

Watch for this

Distribution applies to every term, so the result is 2x+6.

How can I tell I understand it?

Expand and solve a changed expression while explaining why terms may combine.

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.

1Simplify 4(y+2)+2y.
2Which terms can combine in 3x+6+2x?
3A learner rewrites 2(x+3) as 2x+3. What correction is needed?
0 of 3 answeredApply the lesson to a short question, then review the explanation.
4
Finish this lesson

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

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Sources and further reading

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

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