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Sum & difference of cubes

Grade 10

What this lesson shows

Factor x cubed plus 8. Both parts are cubes: x cubed obviously, and 8 because 2 times 2 times 2 is 8. A sum of cubes has its own formula.

Try it yourself

Real questions from this lesson's worksheets — answers below each one.

  1. Factor x³ + 1.
    Show answer
    (x + 1)(x² - x + 1)
  2. Factor x³ - 1.
    Show answer
    (x - 1)(x² + x + 1)
  3. Factor x³ + 8.
    Show answer
    (x + 2)(x² - 2x + 4)
  4. Factor x³ - 8.
    Show answer
    (x - 2)(x² + 2x + 4)

Practise this every day

Eduyro gives your child a short daily worksheet on exactly this skill, and moves them on only once they have it. Watch the lesson, then build the fluency.

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