Calculus Examples

$y = (x^{2} - 4 x - 6) (x^{3} - 5 x^{2} - 3 x)$

Step 1

Differentiate using the Product Rule which states that $\frac{d}{d x} [f (x) g (x)]$ is $f (x) \frac{d}{d x} [g (x)] + g (x) \frac{d}{d x} [f (x)]$ where $f (x) = x^{2} - 4 x - 6$ and $g (x) = x^{3} - 5 x^{2} - 3 x$ .

$(x^{2} - 4 x - 6) \frac{d}{d x} [x^{3} - 5 x^{2} - 3 x] + (x^{3} - 5 x^{2} - 3 x) \frac{d}{d x} [x^{2} - 4 x - 6]$

Step 2

Differentiate.

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Step 2.1

By the Sum Rule, the derivative of $x^{3} - 5 x^{2} - 3 x$ with respect to $x$ is $\frac{d}{d x} [x^{3}] + \frac{d}{d x} [- 5 x^{2}] + \frac{d}{d x} [- 3 x]$ .

$(x^{2} - 4 x - 6) (\frac{d}{d x} [x^{3}] + \frac{d}{d x} [- 5 x^{2}] + \frac{d}{d x} [- 3 x]) + (x^{3} - 5 x^{2} - 3 x) \frac{d}{d x} [x^{2} - 4 x - 6]$

Step 2.2

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 3$ .

$(x^{2} - 4 x - 6) (3 x^{2} + \frac{d}{d x} [- 5 x^{2}] + \frac{d}{d x} [- 3 x]) + (x^{3} - 5 x^{2} - 3 x) \frac{d}{d x} [x^{2} - 4 x - 6]$

Step 2.3

Since $- 5$ is constant with respect to $x$ , the derivative of $- 5 x^{2}$ with respect to $x$ is $- 5 \frac{d}{d x} [x^{2}]$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 5 \frac{d}{d x} [x^{2}] + \frac{d}{d x} [- 3 x]) + (x^{3} - 5 x^{2} - 3 x) \frac{d}{d x} [x^{2} - 4 x - 6]$

Step 2.4

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 2$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 5 (2 x) + \frac{d}{d x} [- 3 x]) + (x^{3} - 5 x^{2} - 3 x) \frac{d}{d x} [x^{2} - 4 x - 6]$

Step 2.5

Multiply $2$ by $- 5$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x + \frac{d}{d x} [- 3 x]) + (x^{3} - 5 x^{2} - 3 x) \frac{d}{d x} [x^{2} - 4 x - 6]$

Step 2.6

Since $- 3$ is constant with respect to $x$ , the derivative of $- 3 x$ with respect to $x$ is $- 3 \frac{d}{d x} [x]$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3 \frac{d}{d x} [x]) + (x^{3} - 5 x^{2} - 3 x) \frac{d}{d x} [x^{2} - 4 x - 6]$

Step 2.7

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 1$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3 \cdot 1) + (x^{3} - 5 x^{2} - 3 x) \frac{d}{d x} [x^{2} - 4 x - 6]$

Step 2.8

Multiply $- 3$ by $1$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) \frac{d}{d x} [x^{2} - 4 x - 6]$

Step 2.9

By the Sum Rule, the derivative of $x^{2} - 4 x - 6$ with respect to $x$ is $\frac{d}{d x} [x^{2}] + \frac{d}{d x} [- 4 x] + \frac{d}{d x} [- 6]$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (\frac{d}{d x} [x^{2}] + \frac{d}{d x} [- 4 x] + \frac{d}{d x} [- 6])$

Step 2.10

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 2$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (2 x + \frac{d}{d x} [- 4 x] + \frac{d}{d x} [- 6])$

Step 2.11

Since $- 4$ is constant with respect to $x$ , the derivative of $- 4 x$ with respect to $x$ is $- 4 \frac{d}{d x} [x]$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (2 x - 4 \frac{d}{d x} [x] + \frac{d}{d x} [- 6])$

Step 2.12

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 1$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (2 x - 4 \cdot 1 + \frac{d}{d x} [- 6])$

Step 2.13

Multiply $- 4$ by $1$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (2 x - 4 + \frac{d}{d x} [- 6])$

Step 2.14

Since $- 6$ is constant with respect to $x$ , the derivative of $- 6$ with respect to $x$ is $0$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (2 x - 4 + 0)$

Step 2.15

Add $2 x - 4$ and $0$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (2 x - 4)$

Step 3

Simplify.

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Step 3.1

Factor $1$ out of $(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (2 x - 4)$ .

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Step 3.1.1

Factor $1$ out of $(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3)$ .

$1 ((x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3)) + (x^{3} - 5 x^{2} - 3 x) (2 x - 4)$

Step 3.1.2

Factor $1$ out of $(x^{3} - 5 x^{2} - 3 x) (2 x - 4)$ .

$1 ((x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3)) + 1 ((x^{3} - 5 x^{2} - 3 x) (2 x - 4))$

Step 3.1.3

Factor $1$ out of $1 ((x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3)) + 1 ((x^{3} - 5 x^{2} - 3 x) (2 x - 4))$ .

$1 ((x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (2 x - 4))$

Step 3.2

Multiply $(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (2 x - 4)$ by $1$ .

$(x^{2} - 4 x - 6) (3 x^{2} - 10 x - 3) + (x^{3} - 5 x^{2} - 3 x) (2 x - 4)$

Step 3.3

Reorder terms.

$(3 x^{2} - 10 x - 3) (x^{2} - 4 x - 6) + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4

Simplify each term.

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Step 3.4.1

Expand $(3 x^{2} - 10 x - 3) (x^{2} - 4 x - 6)$ by multiplying each term in the first expression by each term in the second expression.

$3 x^{2} x^{2} + 3 x^{2} (- 4 x) + 3 x^{2} \cdot - 6 - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2

Simplify each term.

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Step 3.4.2.1

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

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Step 3.4.2.1.1

Move $x^{2}$ .

$3 (x^{2} x^{2}) + 3 x^{2} (- 4 x) + 3 x^{2} \cdot - 6 - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.1.2

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

$3 x^{2 + 2} + 3 x^{2} (- 4 x) + 3 x^{2} \cdot - 6 - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.1.3

Add $2$ and $2$ .

$3 x^{4} + 3 x^{2} (- 4 x) + 3 x^{2} \cdot - 6 - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.2

Rewrite using the commutative property of multiplication.

$3 x^{4} + 3 \cdot - 4 x^{2} x + 3 x^{2} \cdot - 6 - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.3

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

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Step 3.4.2.3.1

Move $x$ .

$3 x^{4} + 3 \cdot - 4 (x \cdot x^{2}) + 3 x^{2} \cdot - 6 - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.3.2

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

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Step 3.4.2.3.2.1

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

$3 x^{4} + 3 \cdot - 4 (x^{1} x^{2}) + 3 x^{2} \cdot - 6 - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.3.2.2

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

$3 x^{4} + 3 \cdot - 4 x^{1 + 2} + 3 x^{2} \cdot - 6 - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.3.3

Add $1$ and $2$ .

$3 x^{4} + 3 \cdot - 4 x^{3} + 3 x^{2} \cdot - 6 - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.4

Multiply $3$ by $- 4$ .

$3 x^{4} - 12 x^{3} + 3 x^{2} \cdot - 6 - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.5

Multiply $- 6$ by $3$ .

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 x \cdot x^{2} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.6

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

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Step 3.4.2.6.1

Move $x^{2}$ .

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 (x^{2} x) - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.6.2

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

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Step 3.4.2.6.2.1

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

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 (x^{2} x^{1}) - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.6.2.2

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

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 x^{2 + 1} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.6.3

Add $2$ and $1$ .

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 x^{3} - 10 x (- 4 x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.7

Rewrite using the commutative property of multiplication.

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 x^{3} - 10 \cdot - 4 x \cdot x - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.8

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

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Step 3.4.2.8.1

Move $x$ .

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 x^{3} - 10 \cdot - 4 (x \cdot x) - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.8.2

Multiply $x$ by $x$ .

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 x^{3} - 10 \cdot - 4 x^{2} - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.9

Multiply $- 10$ by $- 4$ .

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 x^{3} + 40 x^{2} - 10 x \cdot - 6 - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.10

Multiply $- 6$ by $- 10$ .

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 x^{3} + 40 x^{2} + 60 x - 3 x^{2} - 3 (- 4 x) - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.11

Multiply $- 4$ by $- 3$ .

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 x^{3} + 40 x^{2} + 60 x - 3 x^{2} + 12 x - 3 \cdot - 6 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.2.12

Multiply $- 3$ by $- 6$ .

$3 x^{4} - 12 x^{3} - 18 x^{2} - 10 x^{3} + 40 x^{2} + 60 x - 3 x^{2} + 12 x + 18 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.3

Subtract $10 x^{3}$ from $- 12 x^{3}$ .

$3 x^{4} - 22 x^{3} - 18 x^{2} + 40 x^{2} + 60 x - 3 x^{2} + 12 x + 18 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.4

Add $- 18 x^{2}$ and $40 x^{2}$ .

$3 x^{4} - 22 x^{3} + 22 x^{2} + 60 x - 3 x^{2} + 12 x + 18 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.5

Subtract $3 x^{2}$ from $22 x^{2}$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 60 x + 12 x + 18 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.6

Add $60 x$ and $12 x$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + (2 x - 4) (x^{3} - 5 x^{2} - 3 x)$

Step 3.4.7

Expand $(2 x - 4) (x^{3} - 5 x^{2} - 3 x)$ by multiplying each term in the first expression by each term in the second expression.

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x \cdot x^{3} + 2 x (- 5 x^{2}) + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8

Simplify each term.

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Step 3.4.8.1

Multiply $x$ by $x^{3}$ by adding the exponents.

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Step 3.4.8.1.1

Move $x^{3}$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 (x^{3} x) + 2 x (- 5 x^{2}) + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.1.2

Multiply $x^{3}$ by $x$ .

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Step 3.4.8.1.2.1

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

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 (x^{3} x^{1}) + 2 x (- 5 x^{2}) + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.1.2.2

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

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{3 + 1} + 2 x (- 5 x^{2}) + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.1.3

Add $3$ and $1$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} + 2 x (- 5 x^{2}) + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.2

Rewrite using the commutative property of multiplication.

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} + 2 \cdot - 5 x \cdot x^{2} + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.3

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

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Step 3.4.8.3.1

Move $x^{2}$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} + 2 \cdot - 5 (x^{2} x) + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.3.2

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

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Step 3.4.8.3.2.1

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

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} + 2 \cdot - 5 (x^{2} x^{1}) + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.3.2.2

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

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} + 2 \cdot - 5 x^{2 + 1} + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.3.3

Add $2$ and $1$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} + 2 \cdot - 5 x^{3} + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.4

Multiply $2$ by $- 5$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} - 10 x^{3} + 2 x (- 3 x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.5

Rewrite using the commutative property of multiplication.

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} - 10 x^{3} + 2 \cdot - 3 x \cdot x - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.6

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

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Step 3.4.8.6.1

Move $x$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} - 10 x^{3} + 2 \cdot - 3 (x \cdot x) - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.6.2

Multiply $x$ by $x$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} - 10 x^{3} + 2 \cdot - 3 x^{2} - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.7

Multiply $2$ by $- 3$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} - 10 x^{3} - 6 x^{2} - 4 x^{3} - 4 (- 5 x^{2}) - 4 (- 3 x)$

Step 3.4.8.8

Multiply $- 5$ by $- 4$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} - 10 x^{3} - 6 x^{2} - 4 x^{3} + 20 x^{2} - 4 (- 3 x)$

Step 3.4.8.9

Multiply $- 3$ by $- 4$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} - 10 x^{3} - 6 x^{2} - 4 x^{3} + 20 x^{2} + 12 x$

Step 3.4.9

Subtract $4 x^{3}$ from $- 10 x^{3}$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} - 14 x^{3} - 6 x^{2} + 20 x^{2} + 12 x$

Step 3.4.10

Add $- 6 x^{2}$ and $20 x^{2}$ .

$3 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 + 2 x^{4} - 14 x^{3} + 14 x^{2} + 12 x$

Step 3.5

Add $3 x^{4}$ and $2 x^{4}$ .

$5 x^{4} - 22 x^{3} + 19 x^{2} + 72 x + 18 - 14 x^{3} + 14 x^{2} + 12 x$

Step 3.6

Subtract $14 x^{3}$ from $- 22 x^{3}$ .

$5 x^{4} - 36 x^{3} + 19 x^{2} + 72 x + 18 + 14 x^{2} + 12 x$

Step 3.7

Add $19 x^{2}$ and $14 x^{2}$ .

$5 x^{4} - 36 x^{3} + 33 x^{2} + 72 x + 18 + 12 x$

Step 3.8

Add $72 x$ and $12 x$ .

$5 x^{4} - 36 x^{3} + 33 x^{2} + 84 x + 18$