Evaluate (x+9)(x-9)

$(x + 9) (x - 9)$

Step 1

Expand $(x + 9) (x - 9)$ using the FOIL Method.

Apply the distributive property.

$x (x - 9) + 9 (x - 9)$

Apply the distributive property.

$x \cdot x + x \cdot - 9 + 9 (x - 9)$

Apply the distributive property.

$x \cdot x + x \cdot - 9 + 9 x + 9 \cdot - 9$

Step 2

Simplify terms.

Combine the opposite terms in $x \cdot x + x \cdot - 9 + 9 x + 9 \cdot - 9$ .

Reorder the factors in the terms $x \cdot - 9$ and $9 x$ .

$x \cdot x - 9 x + 9 x + 9 \cdot - 9$

Add $- 9 x$ and $9 x$ .

$x \cdot x + 0 + 9 \cdot - 9$

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

$x \cdot x + 9 \cdot - 9$

Simplify each term.

Multiply $x$ by $x$ .

$x^{2} + 9 \cdot - 9$

Multiply $9$ by $- 9$ .

$x^{2} - 81$