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. Find the coefficient of x^4 in the binomial expansion of (x + 4)^5.
4 · 4 · 5 · Binomial theorem coefficie…
2. Find the coefficient of x^1 in the binomial expansion of (x + 5)^3.
1 · 5 · 3 · Binomial theorem coefficie…
3. Find the coefficient of x^3 in the binomial expansion of (x + 7)^4.
3 · 7 · 4 · Binomial theorem coefficie…
4. Find the coefficient of x^3 in the binomial expansion of (x + 5)^5.
3 · 5 · 5 · Binomial theorem coefficie…
5. Find the coefficient of x^2 in the binomial expansion of (x + 6)^3.
2 · 6 · 3 · Binomial theorem coefficie…
6. Find the coefficient of x^1 in the binomial expansion of (x + 7)^3.
1 · 7 · 3 · Binomial theorem coefficie…
7. Find the coefficient of x^4 in the binomial expansion of (x + 6)^5.
4 · 6 · 5 · Binomial theorem coefficie…
8. Find the coefficient of x^3 in the binomial expansion of (x + 6)^4.
3 · 6 · 4 · Binomial theorem coefficie…
9. Find the coefficient of x^1 in the binomial expansion of (x + 1)^3.
1 · 1 · 3 · Binomial theorem coefficie…
10. Find the coefficient of x^2 in the binomial expansion of (x + 6)^5.
2 · 6 · 5 · Binomial theorem coefficie…
11. Find the coefficient of x^1 in the binomial expansion of (x + 5)^6.
1 · 5 · 6 · Binomial theorem coefficie…
12. Find the coefficient of x^2 in the binomial expansion of (x + 7)^6.
2 · 7 · 6 · Binomial theorem coefficie…

12 questions · Seed 57 · 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. Find the coefficient of x^4 in the binomial expansion of (x + 4)^5.
20
By the binomial theorem, the x^4 term has coefficient C(5, 1) × 4^1 = 5 × 4 = 20.
2. Find the coefficient of x^1 in the binomial expansion of (x + 5)^3.
75
By the binomial theorem, the x^1 term has coefficient C(3, 2) × 5^2 = 3 × 25 = 75.
3. Find the coefficient of x^3 in the binomial expansion of (x + 7)^4.
28
By the binomial theorem, the x^3 term has coefficient C(4, 1) × 7^1 = 4 × 7 = 28.
4. Find the coefficient of x^3 in the binomial expansion of (x + 5)^5.
250
By the binomial theorem, the x^3 term has coefficient C(5, 2) × 5^2 = 10 × 25 = 250.
5. Find the coefficient of x^2 in the binomial expansion of (x + 6)^3.
18
By the binomial theorem, the x^2 term has coefficient C(3, 1) × 6^1 = 3 × 6 = 18.
6. Find the coefficient of x^1 in the binomial expansion of (x + 7)^3.
147
By the binomial theorem, the x^1 term has coefficient C(3, 2) × 7^2 = 3 × 49 = 147.
7. Find the coefficient of x^4 in the binomial expansion of (x + 6)^5.
30
By the binomial theorem, the x^4 term has coefficient C(5, 1) × 6^1 = 5 × 6 = 30.
8. Find the coefficient of x^3 in the binomial expansion of (x + 6)^4.
24
By the binomial theorem, the x^3 term has coefficient C(4, 1) × 6^1 = 4 × 6 = 24.
9. Find the coefficient of x^1 in the binomial expansion of (x + 1)^3.
3
By the binomial theorem, the x^1 term has coefficient C(3, 2) × 1^2 = 3 × 1 = 3.
10. Find the coefficient of x^2 in the binomial expansion of (x + 6)^5.
2160
By the binomial theorem, the x^2 term has coefficient C(5, 3) × 6^3 = 10 × 216 = 2160.
11. Find the coefficient of x^1 in the binomial expansion of (x + 5)^6.
18750
By the binomial theorem, the x^1 term has coefficient C(6, 5) × 5^5 = 6 × 3125 = 18750.
12. Find the coefficient of x^2 in the binomial expansion of (x + 7)^6.
36015
By the binomial theorem, the x^2 term has coefficient C(6, 4) × 7^4 = 15 × 2401 = 36015.

12 questions · Seed 57 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 16-18

Binomial theorem coefficients

Take your time. Show your thinking.

1. Find the coefficient of x^4 in the binomial expansion of (x + 4)^5.
4 · 4 · 5 · Binomial theorem coefficie…
2. Find the coefficient of x^1 in the binomial expansion of (x + 5)^3.
1 · 5 · 3 · Binomial theorem coefficie…
3. Find the coefficient of x^3 in the binomial expansion of (x + 7)^4.
3 · 7 · 4 · Binomial theorem coefficie…
4. Find the coefficient of x^3 in the binomial expansion of (x + 5)^5.
3 · 5 · 5 · Binomial theorem coefficie…
5. Find the coefficient of x^2 in the binomial expansion of (x + 6)^3.
2 · 6 · 3 · Binomial theorem coefficie…
6. Find the coefficient of x^1 in the binomial expansion of (x + 7)^3.
1 · 7 · 3 · Binomial theorem coefficie…
7. Find the coefficient of x^4 in the binomial expansion of (x + 6)^5.
4 · 6 · 5 · Binomial theorem coefficie…
8. Find the coefficient of x^3 in the binomial expansion of (x + 6)^4.
3 · 6 · 4 · Binomial theorem coefficie…
9. Find the coefficient of x^1 in the binomial expansion of (x + 1)^3.
1 · 1 · 3 · Binomial theorem coefficie…
10. Find the coefficient of x^2 in the binomial expansion of (x + 6)^5.
2 · 6 · 5 · Binomial theorem coefficie…
11. Find the coefficient of x^1 in the binomial expansion of (x + 5)^6.
1 · 5 · 6 · Binomial theorem coefficie…
12. Find the coefficient of x^2 in the binomial expansion of (x + 7)^6.
2 · 7 · 6 · Binomial theorem coefficie…

12 questions · Seed 57 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 16-18

Binomial theorem coefficients

Answers and reasoning. Review before teaching.

1. Find the coefficient of x^4 in the binomial expansion of (x + 4)^5.
20
By the binomial theorem, the x^4 term has coefficient C(5, 1) × 4^1 = 5 × 4 = 20.
2. Find the coefficient of x^1 in the binomial expansion of (x + 5)^3.
75
By the binomial theorem, the x^1 term has coefficient C(3, 2) × 5^2 = 3 × 25 = 75.
3. Find the coefficient of x^3 in the binomial expansion of (x + 7)^4.
28
By the binomial theorem, the x^3 term has coefficient C(4, 1) × 7^1 = 4 × 7 = 28.
4. Find the coefficient of x^3 in the binomial expansion of (x + 5)^5.
250
By the binomial theorem, the x^3 term has coefficient C(5, 2) × 5^2 = 10 × 25 = 250.
5. Find the coefficient of x^2 in the binomial expansion of (x + 6)^3.
18
By the binomial theorem, the x^2 term has coefficient C(3, 1) × 6^1 = 3 × 6 = 18.
6. Find the coefficient of x^1 in the binomial expansion of (x + 7)^3.
147
By the binomial theorem, the x^1 term has coefficient C(3, 2) × 7^2 = 3 × 49 = 147.
7. Find the coefficient of x^4 in the binomial expansion of (x + 6)^5.
30
By the binomial theorem, the x^4 term has coefficient C(5, 1) × 6^1 = 5 × 6 = 30.
8. Find the coefficient of x^3 in the binomial expansion of (x + 6)^4.
24
By the binomial theorem, the x^3 term has coefficient C(4, 1) × 6^1 = 4 × 6 = 24.
9. Find the coefficient of x^1 in the binomial expansion of (x + 1)^3.
3
By the binomial theorem, the x^1 term has coefficient C(3, 2) × 1^2 = 3 × 1 = 3.
10. Find the coefficient of x^2 in the binomial expansion of (x + 6)^5.
2160
By the binomial theorem, the x^2 term has coefficient C(5, 3) × 6^3 = 10 × 216 = 2160.
11. Find the coefficient of x^1 in the binomial expansion of (x + 5)^6.
18750
By the binomial theorem, the x^1 term has coefficient C(6, 5) × 5^5 = 6 × 3125 = 18750.
12. Find the coefficient of x^2 in the binomial expansion of (x + 7)^6.
36015
By the binomial theorem, the x^2 term has coefficient C(6, 4) × 7^4 = 15 × 2401 = 36015.

12 questions · Seed 57 · Age guidance, not curriculum certification