Trigonometry Examples

$(x + 3) (x - 3)$

Step 1

Expand $(x + 3) (x - 3)$ using the FOIL Method.

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Step 1.1

Apply the distributive property.

$x (x - 3) + 3 (x - 3)$

Step 1.2

Apply the distributive property.

$x \cdot x + x \cdot - 3 + 3 (x - 3)$

Step 1.3

Apply the distributive property.

$x \cdot x + x \cdot - 3 + 3 x + 3 \cdot - 3$

Step 2

Simplify terms.

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Step 2.1

Combine the opposite terms in $x \cdot x + x \cdot - 3 + 3 x + 3 \cdot - 3$ .

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Step 2.1.1

Reorder the factors in the terms $x \cdot - 3$ and $3 x$ .

$x \cdot x - 3 x + 3 x + 3 \cdot - 3$

Step 2.1.2

Add $- 3 x$ and $3 x$ .

$x \cdot x + 0 + 3 \cdot - 3$

Step 2.1.3

Add $x \cdot x$ and $0$ .

$x \cdot x + 3 \cdot - 3$

Step 2.2

Simplify each term.

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Step 2.2.1

Multiply $x$ by $x$ .

$x^{2} + 3 \cdot - 3$

Step 2.2.2

Multiply $3$ by $- 3$ .

$x^{2} - 9$