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MathsAges 16-18

Binomial theorem coefficients

Use combinations C(n, r) and powers to find specific coefficients in the binomial expansion of (x + k)ⁿ. Review suitability for your learners before teaching.

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Worksheet StudioPractice pack · Ages 16-18

Binomial theorem coefficients

Take your time. Show your thinking.

  1. 1. Find the coefficient of x^1 in the binomial expansion of (x + 3)^4.

    LHS=RHS
    1 · 3 · 4 · Binomial theorem coefficie…
  2. 2. Find the coefficient of x^3 in the binomial expansion of (x + 1)^6.

    LHS=RHS
    3 · 1 · 6 · Binomial theorem coefficie…
  3. 3. Find the coefficient of x^2 in the binomial expansion of (x + 4)^3.

    LHS=RHS
    2 · 4 · 3 · Binomial theorem coefficie…
  4. 4. Find the coefficient of x^3 in the binomial expansion of (x + 3)^6.

    LHS=RHS
    3 · 3 · 6 · Binomial theorem coefficie…
  5. 5. Find the coefficient of x^5 in the binomial expansion of (x + 2)^6.

    LHS=RHS
    5 · 2 · 6 · Binomial theorem coefficie…
  6. 6. Find the coefficient of x^1 in the binomial expansion of (x + 4)^6.

    LHS=RHS
    1 · 4 · 6 · Binomial theorem coefficie…
  7. 7. Find the coefficient of x^1 in the binomial expansion of (x + 4)^4.

    LHS=RHS
    1 · 4 · 4 · Binomial theorem coefficie…
  8. 8. Find the coefficient of x^4 in the binomial expansion of (x + 7)^5.

    LHS=RHS
    4 · 7 · 5 · Binomial theorem coefficie…
  9. 9. Find the coefficient of x^1 in the binomial expansion of (x + 6)^4.

    LHS=RHS
    1 · 6 · 4 · Binomial theorem coefficie…
  10. 10. Find the coefficient of x^4 in the binomial expansion of (x + 1)^6.

    LHS=RHS
    4 · 1 · 6 · Binomial theorem coefficie…
  11. 11. Find the coefficient of x^1 in the binomial expansion of (x + 5)^4.

    LHS=RHS
    1 · 5 · 4 · Binomial theorem coefficie…
  12. 12. Find the coefficient of x^3 in the binomial expansion of (x + 5)^4.

    LHS=RHS
    3 · 5 · 4 · Binomial theorem coefficie…
12 questions · Seed 42 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 16-18

Binomial theorem coefficients

Answers and reasoning. Review before teaching.

  1. 1. Find the coefficient of x^1 in the binomial expansion of (x + 3)^4.

    108

    By the binomial theorem, the x^1 term has coefficient C(4, 3) × 3^3 = 4 × 27 = 108.

  2. 2. Find the coefficient of x^3 in the binomial expansion of (x + 1)^6.

    20

    By the binomial theorem, the x^3 term has coefficient C(6, 3) × 1^3 = 20 × 1 = 20.

  3. 3. Find the coefficient of x^2 in the binomial expansion of (x + 4)^3.

    12

    By the binomial theorem, the x^2 term has coefficient C(3, 1) × 4^1 = 3 × 4 = 12.

  4. 4. Find the coefficient of x^3 in the binomial expansion of (x + 3)^6.

    540

    By the binomial theorem, the x^3 term has coefficient C(6, 3) × 3^3 = 20 × 27 = 540.

  5. 5. Find the coefficient of x^5 in the binomial expansion of (x + 2)^6.

    12

    By the binomial theorem, the x^5 term has coefficient C(6, 1) × 2^1 = 6 × 2 = 12.

  6. 6. Find the coefficient of x^1 in the binomial expansion of (x + 4)^6.

    6144

    By the binomial theorem, the x^1 term has coefficient C(6, 5) × 4^5 = 6 × 1024 = 6144.

  7. 7. Find the coefficient of x^1 in the binomial expansion of (x + 4)^4.

    256

    By the binomial theorem, the x^1 term has coefficient C(4, 3) × 4^3 = 4 × 64 = 256.

  8. 8. Find the coefficient of x^4 in the binomial expansion of (x + 7)^5.

    35

    By the binomial theorem, the x^4 term has coefficient C(5, 1) × 7^1 = 5 × 7 = 35.

  9. 9. Find the coefficient of x^1 in the binomial expansion of (x + 6)^4.

    864

    By the binomial theorem, the x^1 term has coefficient C(4, 3) × 6^3 = 4 × 216 = 864.

  10. 10. Find the coefficient of x^4 in the binomial expansion of (x + 1)^6.

    15

    By the binomial theorem, the x^4 term has coefficient C(6, 2) × 1^2 = 15 × 1 = 15.

  11. 11. Find the coefficient of x^1 in the binomial expansion of (x + 5)^4.

    500

    By the binomial theorem, the x^1 term has coefficient C(4, 3) × 5^3 = 4 × 125 = 500.

  12. 12. Find the coefficient of x^3 in the binomial expansion of (x + 5)^4.

    20

    By the binomial theorem, the x^3 term has coefficient C(4, 1) × 5^1 = 4 × 5 = 20.

12 questions · Seed 42 · Age guidance, not curriculum certification