Practice Binomial Theorem in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

The binomial theorem gives the expansion of (a + b)^n as a sum of terms involving binomial coefficients: (a+b)^n = sum of C(n,k) * a^(n-k) * b^k. Each coefficient (nk) counts the number of ways to choose k copies of b from n factors.

Each term of (a+b)n picks 'a' or 'b' from each factor. (nk) counts how many ways to pick k b's.

Showing a random 20 of 50 problems.

Example 1

medium
Expand (x+2)3 using the Binomial Theorem.

Example 2

easy
Write the coefficients in the expansion of (a+b)4.

Example 3

medium
Sum of coefficients of (3x−2)5 when x=1?

Example 4

medium
Use the binomial theorem to compute 113 by writing 11=10+1.

Example 5

challenge
Prove that the sum of the coefficients in (a+b)n equals 2n.

Example 6

hard
Find the coefficient of x6 in (1+x+x2)4.

Example 7

challenge
Prove the Vandermonde identity: (m+nr)=∑k=0r(mk)(nr−k).

Example 8

medium
Find the coefficient of x4 in (2x2+3)4.

Example 9

medium
What is ∑k=0n(nk)=?

Example 10

hard
Find the coefficient of x3 in the expansion of (2x+3)5.

Example 11

hard
In (2x−3y)4, find the coefficient of x2y2.

Example 12

challenge
Find the term containing x4 in (x2+2x)5.

Example 13

medium
Find the coefficient of x2 in (2x+3)4.

Example 14

easy
Compute (52).

Example 15

medium
Find the coefficient of x2y3 in (x+y)5.

Example 16

easy
Compute (73).

Example 17

easy
Compute (63).

Example 18

easy
Compute the binomial coefficient (42).

Example 19

easy
What is the coefficient of a2b in the expansion of (a+b)3?

Example 20

medium
Expand (1+x)4 and use it to evaluate (1.01)4 to 4 decimal places.