Finite Math Examples

{(2 k + 1)}^{3}

${(2 k + 1)}^{3}$

Step 1

Use the binomial expansion theorem to find each term. The binomial theorem states

{(a + b)}^{n} = n \sum k = 0 n C k \cdot (a^{n - k} b^{k})

${(a + b)}^{n} = \sum_{k = 0}^{n} n C k \cdot (a^{n - k} b^{k})$ .

3 \sum k = 0 \frac{3!}{(3 - k)! k!} \cdot {(2 k)}^{3 - k} \cdot {(1)}^{k}

$\sum_{k = 0}^{3} \frac{3!}{(3 - k)! k!} \cdot {(2 k)}^{3 - k} \cdot {(1)}^{k}$

Step 2

Expand the summation.

\frac{3!}{(3 - 0)! 0!} \cdot {(2 k)}^{3 - 0} \cdot {(1)}^{0} + \frac{3!}{(3 - 1)! 1!} \cdot {(2 k)}^{3 - 1} \cdot {(1)}^{1} + \frac{3!}{(3 - 2)! 2!} \cdot {(2 k)}^{3 - 2} \cdot {(1)}^{2} + \frac{3!}{(3 - 3)! 3!} \cdot {(2 k)}^{3 - 3} \cdot {(1)}^{3}

$\frac{3!}{(3 - 0)! 0!} \cdot {(2 k)}^{3 - 0} \cdot {(1)}^{0} + \frac{3!}{(3 - 1)! 1!} \cdot {(2 k)}^{3 - 1} \cdot {(1)}^{1} + \frac{3!}{(3 - 2)! 2!} \cdot {(2 k)}^{3 - 2} \cdot {(1)}^{2} + \frac{3!}{(3 - 3)! 3!} \cdot {(2 k)}^{3 - 3} \cdot {(1)}^{3}$

Step 3

Simplify the exponents for each term of the expansion.

1 \cdot {(2 k)}^{3} \cdot {(1)}^{0} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$1 \cdot {(2 k)}^{3} \cdot {(1)}^{0} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4

Simplify each term.

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Step 4.1

Multiply

1

$1$ by

{(1)}^{0}

${(1)}^{0}$ by adding the exponents.

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Step 4.1.1

Move

{(1)}^{0}

${(1)}^{0}$ .

{(1)}^{0} \cdot 1 \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

${(1)}^{0} \cdot 1 \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.1.2

Multiply

{(1)}^{0}

${(1)}^{0}$ by

1

$1$ .

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Step 4.1.2.1

Raise

1

$1$ to the power of

1

$1$ .

{(1)}^{0} \cdot 1^{1} \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

${(1)}^{0} \cdot 1^{1} \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.1.2.2

Use the power rule

a^{m} a^{n} = a^{m + n}

$a^{m} a^{n} = a^{m + n}$ to combine exponents.

1^{0 + 1} \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$1^{0 + 1} \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

1^{0 + 1} \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$1^{0 + 1} \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.1.3

Add

0

$0$ and

1

$1$ .

1^{1} \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$1^{1} \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

1^{1} \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$1^{1} \cdot {(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.2

Simplify

1^{1} \cdot {(2 k)}^{3}

$1^{1} \cdot {(2 k)}^{3}$ .

{(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

${(2 k)}^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.3

Apply the product rule to

2 k

$2 k$ .

2^{3} k^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$2^{3} k^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.4

Raise

2

$2$ to the power of

3

$3$ .

8 k^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$8 k^{3} + 3 \cdot {(2 k)}^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.5

Apply the product rule to

2 k

$2 k$ .

8 k^{3} + 3 \cdot (2^{2} k^{2}) \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$8 k^{3} + 3 \cdot (2^{2} k^{2}) \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.6

Raise

2

$2$ to the power of

2

$2$ .

8 k^{3} + 3 \cdot (4 k^{2}) \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$8 k^{3} + 3 \cdot (4 k^{2}) \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.7

Multiply

4

$4$ by

3

$3$ .

8 k^{3} + 12 k^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$8 k^{3} + 12 k^{2} \cdot {(1)}^{1} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.8

Evaluate the exponent.

8 k^{3} + 12 k^{2} \cdot 1 + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$8 k^{3} + 12 k^{2} \cdot 1 + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.9

Multiply

12

$12$ by

1

$1$ .

8 k^{3} + 12 k^{2} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}

$8 k^{3} + 12 k^{2} + 3 \cdot {(2 k)}^{1} \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.10

Simplify.

$8 k^{3} + 12 k^{2} + 3 \cdot (2 k) \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.11

Multiply

$2$ by

$3$ .

$8 k^{3} + 12 k^{2} + 6 k \cdot {(1)}^{2} + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.12

One to any power is one.

$8 k^{3} + 12 k^{2} + 6 k \cdot 1 + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.13

Multiply

$6$ by

$1$ .

$8 k^{3} + 12 k^{2} + 6 k + 1 \cdot {(2 k)}^{0} \cdot {(1)}^{3}$

Step 4.14

Multiply

$1$ by

${(1)}^{3}$ by adding the exponents.

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Step 4.14.1

Move

${(1)}^{3}$ .

$8 k^{3} + 12 k^{2} + 6 k + {(1)}^{3} \cdot 1 \cdot {(2 k)}^{0}$

Step 4.14.2

Multiply

${(1)}^{3}$ by

$1$ .

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Step 4.14.2.1

Raise

$1$ to the power of

$1$ .

$8 k^{3} + 12 k^{2} + 6 k + {(1)}^{3} \cdot 1^{1} \cdot {(2 k)}^{0}$

Step 4.14.2.2

Use the power rule

$a^{m} a^{n} = a^{m + n}$ to combine exponents.

$8 k^{3} + 12 k^{2} + 6 k + 1^{3 + 1} \cdot {(2 k)}^{0}$

Step 4.14.3

Add

$3$ and

$1$ .

$8 k^{3} + 12 k^{2} + 6 k + 1^{4} \cdot {(2 k)}^{0}$

Step 4.15

Simplify

$1^{4} \cdot {(2 k)}^{0}$ .

$8 k^{3} + 12 k^{2} + 6 k + 1^{4}$

Step 4.16

One to any power is one.

$8 k^{3} + 12 k^{2} + 6 k + 1$