Algebra Examples

${(x^{- 1} + 2 y^{- 1})}^{4}$

Step 1

Rewrite the expression using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

${(\frac{1}{x} + 2 y^{- 1})}^{4}$

Step 2

Rewrite the expression using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

${(\frac{1}{x} + 2 (\frac{1}{y}))}^{4}$

Step 3

Combine $2$ and $\frac{1}{y}$ .

${(\frac{1}{x} + \frac{2}{y})}^{4}$

Step 4

Pascal's Triangle can be displayed as such:

$1$

$1 - 1$

$1 - 2 - 1$

$1 - 3 - 3 - 1$

$1 - 4 - 6 - 4 - 1$

The triangle can be used to calculate the coefficients of the expansion of ${(a + b)}^{n}$ by taking the exponent $n$ and adding $1$ . The coefficients will correspond with line $n + 1$ of the triangle. For ${(\frac{1}{x} + \frac{2}{y})}^{4}$ , $n = 4$ so the coefficients of the expansion will correspond with line $5$ .

Step 5

The expansion follows the rule ${(a + b)}^{n} = c_{0} a^{n} b^{0} + c_{1} a^{n - 1} b^{1} + c_{n - 1} a^{1} b^{n - 1} + c_{n} a^{0} b^{n}$ . The values of the coefficients, from the triangle, are $1 - 4 - 6 - 4 - 1$ .

${(1 a^{4} b^{0} + 4 a^{3} b + 6 a^{2} b^{2} + 4 a b^{3} + 1 a^{0} b^{4})}^{4}$

Step 6

Substitute the actual values of $a$ $\frac{1}{x}$ and $b$ $\frac{2}{y}$ into the expression.

$1 {(\frac{1}{x})}^{4} {(\frac{2}{y})}^{0} + 4 {(\frac{1}{x})}^{3} {(\frac{2}{y})}^{1} + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 {(\frac{1}{x})}^{1} {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4}$

Step 7

Simplify each term.

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Step 7.1

Multiply ${(\frac{1}{x})}^{4}$ by $1$ .

${({(\frac{1}{x})}^{4} {(\frac{2}{y})}^{0} + 4 {(\frac{1}{x})}^{3} (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.2

Apply the product rule to $\frac{1}{x}$ .

${(\frac{1^{4}}{x^{4}} \cdot {(\frac{2}{y})}^{0} + 4 {(\frac{1}{x})}^{3} (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.3

One to any power is one.

${(\frac{1}{x^{4}} \cdot {(\frac{2}{y})}^{0} + 4 {(\frac{1}{x})}^{3} (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.4

Apply the product rule to $\frac{2}{y}$ .

${(\frac{1}{x^{4}} \cdot \frac{2^{0}}{y^{0}} + 4 {(\frac{1}{x})}^{3} (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.5

Combine.

${(\frac{1 \cdot 2^{0}}{x^{4} y^{0}} + 4 {(\frac{1}{x})}^{3} (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.6

Multiply $2^{0}$ by $1$ .

${(\frac{2^{0}}{x^{4} y^{0}} + 4 {(\frac{1}{x})}^{3} (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.7

Anything raised to $0$ is $1$ .

${(\frac{2^{0}}{x^{4} \cdot 1} + 4 {(\frac{1}{x})}^{3} (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.8

Anything raised to $0$ is $1$ .

${(\frac{1}{x^{4} \cdot 1} + 4 {(\frac{1}{x})}^{3} (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.9

Multiply $x^{4}$ by $1$ .

${(\frac{1}{x^{4}} + 4 {(\frac{1}{x})}^{3} (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.10

Apply the product rule to $\frac{1}{x}$ .

${(\frac{1}{x^{4}} + 4 (\frac{1^{3}}{x^{3}}) \cdot (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.11

One to any power is one.

${(\frac{1}{x^{4}} + 4 (\frac{1}{x^{3}}) \cdot (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.12

Combine $4$ and $\frac{1}{x^{3}}$ .

${(\frac{1}{x^{4}} + \frac{4}{x^{3}} \cdot (\frac{2}{y}) + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.13

Simplify.

${(\frac{1}{x^{4}} + \frac{4}{x^{3}} \cdot \frac{2}{y} + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.14

Combine.

${(\frac{1}{x^{4}} + \frac{4 \cdot 2}{x^{3} y} + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.15

Multiply $4$ by $2$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + 6 {(\frac{1}{x})}^{2} {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.16

Apply the product rule to $\frac{1}{x}$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + 6 (\frac{1^{2}}{x^{2}}) \cdot {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.17

One to any power is one.

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + 6 (\frac{1}{x^{2}}) \cdot {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.18

Combine $6$ and $\frac{1}{x^{2}}$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{6}{x^{2}} \cdot {(\frac{2}{y})}^{2} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.19

Apply the product rule to $\frac{2}{y}$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{6}{x^{2}} \cdot \frac{2^{2}}{y^{2}} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.20

Combine.

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{6 \cdot 2^{2}}{x^{2} y^{2}} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.21

Raise $2$ to the power of $2$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{6 \cdot 4}{x^{2} y^{2}} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.22

Multiply $6$ by $4$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + 4 (\frac{1}{x}) {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.23

Simplify.

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + 4 (\frac{1}{x}) \cdot {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.24

Combine $4$ and $\frac{1}{x}$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{4}{x} \cdot {(\frac{2}{y})}^{3} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.25

Apply the product rule to $\frac{2}{y}$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{4}{x} \cdot \frac{2^{3}}{y^{3}} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.26

Combine.

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{4 \cdot 2^{3}}{x y^{3}} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.27

Simplify the numerator.

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Step 7.27.1

Rewrite $4$ as $2^{2}$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{2^{2} \cdot 2^{3}}{x y^{3}} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.27.2

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{2^{2 + 3}}{x y^{3}} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.27.3

Add $2$ and $3$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{2^{5}}{x y^{3}} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.28

Raise $2$ to the power of $5$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{32}{x y^{3}} + 1 {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.29

Multiply ${(\frac{1}{x})}^{0}$ by $1$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{32}{x y^{3}} + {(\frac{1}{x})}^{0} {(\frac{2}{y})}^{4})}^{4}$

Step 7.30

Apply the product rule to $\frac{1}{x}$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{32}{x y^{3}} + \frac{1^{0}}{x^{0}} \cdot {(\frac{2}{y})}^{4})}^{4}$

Step 7.31

Anything raised to $0$ is $1$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{32}{x y^{3}} + \frac{1}{x^{0}} \cdot {(\frac{2}{y})}^{4})}^{4}$

Step 7.32

Anything raised to $0$ is $1$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{32}{x y^{3}} + \frac{1}{1} \cdot {(\frac{2}{y})}^{4})}^{4}$

Step 7.33

Divide $1$ by $1$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{32}{x y^{3}} + 1 {(\frac{2}{y})}^{4})}^{4}$

Step 7.34

Multiply ${(\frac{2}{y})}^{4}$ by $1$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{32}{x y^{3}} + {(\frac{2}{y})}^{4})}^{4}$

Step 7.35

Apply the product rule to $\frac{2}{y}$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{32}{x y^{3}} + \frac{2^{4}}{y^{4}})}^{4}$

Step 7.36

Raise $2$ to the power of $4$ .

${(\frac{1}{x^{4}} + \frac{8}{x^{3} y} + \frac{24}{x^{2} y^{2}} + \frac{32}{x y^{3}} + \frac{16}{y^{4}})}^{4}$