Algebra Examples

$y + \frac{2 y^{3}}{x^{3} - y^{3}}$

Step 1

Since both terms are perfect cubes, factor using the difference of cubes formula, $a^{3} - b^{3} = (a - b) (a^{2} + a b + b^{2})$ where $a = x$ and $b = y$ .

$y + \frac{2 y^{3}}{(x - y) (x^{2} + x y + y^{2})}$

Step 2

To write $y$ as a fraction with a common denominator, multiply by $\frac{(x - y) (x^{2} + x y + y^{2})}{(x - y) (x^{2} + x y + y^{2})}$ .

$y \cdot \frac{(x - y) (x^{2} + x y + y^{2})}{(x - y) (x^{2} + x y + y^{2})} + \frac{2 y^{3}}{(x - y) (x^{2} + x y + y^{2})}$

Step 3

Simplify terms.

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Step 3.1

Combine $y$ and $\frac{(x - y) (x^{2} + x y + y^{2})}{(x - y) (x^{2} + x y + y^{2})}$ .

$\frac{y ((x - y) (x^{2} + x y + y^{2}))}{(x - y) (x^{2} + x y + y^{2})} + \frac{2 y^{3}}{(x - y) (x^{2} + x y + y^{2})}$

Step 3.2

Combine the numerators over the common denominator.

$\frac{y ((x - y) (x^{2} + x y + y^{2})) + 2 y^{3}}{(x - y) (x^{2} + x y + y^{2})}$

Step 4

Simplify the numerator.

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Step 4.1

Factor $y$ out of $y ((x - y) (x^{2} + x y + y^{2})) + 2 y^{3}$ .

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Step 4.1.1

Factor $y$ out of $2 y^{3}$ .

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

Step 4.1.2

Factor $y$ out of $y ((x - y) (x^{2} + x y + y^{2})) + y (2 y^{2})$ .

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

Step 4.2

Expand $(x - y) (x^{2} + x y + y^{2})$ by multiplying each term in the first expression by each term in the second expression.

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

Step 4.3

Simplify each term.

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Step 4.3.1

Multiply $x$ by $x^{2}$ by adding the exponents.

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Step 4.3.1.1

Multiply $x$ by $x^{2}$ .

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Step 4.3.1.1.1

Raise $x$ to the power of $1$ .

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

Step 4.3.1.1.2

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

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

Step 4.3.1.2

Add $1$ and $2$ .

$\frac{y (x^{3} + x (x y) + x y^{2} - y x^{2} - y (x y) - y \cdot y^{2} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.3.2

Multiply $x$ by $x$ by adding the exponents.

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Step 4.3.2.1

Move $x$ .

$\frac{y (x^{3} + x \cdot x y + x y^{2} - y x^{2} - y (x y) - y \cdot y^{2} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.3.2.2

Multiply $x$ by $x$ .

$\frac{y (x^{3} + x^{2} y + x y^{2} - y x^{2} - y (x y) - y \cdot y^{2} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.3.3

Multiply $y$ by $y$ by adding the exponents.

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Step 4.3.3.1

Move $y$ .

$\frac{y (x^{3} + x^{2} y + x y^{2} - y x^{2} - (y \cdot y) x - y \cdot y^{2} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.3.3.2

Multiply $y$ by $y$ .

$\frac{y (x^{3} + x^{2} y + x y^{2} - y x^{2} - y^{2} x - y \cdot y^{2} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.3.4

Multiply $y$ by $y^{2}$ by adding the exponents.

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Step 4.3.4.1

Move $y^{2}$ .

$\frac{y (x^{3} + x^{2} y + x y^{2} - y x^{2} - y^{2} x - (y^{2} y) + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.3.4.2

Multiply $y^{2}$ by $y$ .

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Step 4.3.4.2.1

Raise $y$ to the power of $1$ .

$\frac{y (x^{3} + x^{2} y + x y^{2} - y x^{2} - y^{2} x - (y^{2} y^{1}) + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.3.4.2.2

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

$\frac{y (x^{3} + x^{2} y + x y^{2} - y x^{2} - y^{2} x - y^{2 + 1} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.3.4.3

Add $2$ and $1$ .

$\frac{y (x^{3} + x^{2} y + x y^{2} - y x^{2} - y^{2} x - y^{3} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.4

Combine the opposite terms in $x^{3} + x^{2} y + x y^{2} - y x^{2} - y^{2} x - y^{3}$ .

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Step 4.4.1

Reorder the factors in the terms $x^{2} y$ and $- y x^{2}$ .

$\frac{y (x^{3} + x^{2} y + x y^{2} - x^{2} y - y^{2} x - y^{3} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.4.2

Subtract $x^{2} y$ from $x^{2} y$ .

$\frac{y (x^{3} + x y^{2} + 0 - y^{2} x - y^{3} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.4.3

Add $x^{3} + x y^{2}$ and $0$ .

$\frac{y (x^{3} + x y^{2} - y^{2} x - y^{3} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.4.4

Reorder the factors in the terms $x y^{2}$ and $- y^{2} x$ .

$\frac{y (x^{3} + y^{2} x - y^{2} x - y^{3} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.4.5

Subtract $y^{2} x$ from $y^{2} x$ .

$\frac{y (x^{3} + 0 - y^{3} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$

Step 4.4.6

Add $x^{3}$ and $0$ .

$\frac{y (x^{3} - y^{3} + 2 y^{2})}{(x - y) (x^{2} + x y + y^{2})}$