Simplify (8x+9)(8x-9)

$(8 x + 9) (8 x - 9)$

Step 1

Expand $(8 x + 9) (8 x - 9)$ using the FOIL Method.

Apply the distributive property.

$8 x (8 x - 9) + 9 (8 x - 9)$

Apply the distributive property.

$8 x (8 x) + 8 x \cdot - 9 + 9 (8 x - 9)$

Apply the distributive property.

$8 x (8 x) + 8 x \cdot - 9 + 9 (8 x) + 9 \cdot - 9$

Step 2

Simplify and combine like terms.

Simplify each term.

Rewrite using the commutative property of multiplication.

$8 \cdot 8 x \cdot x + 8 x \cdot - 9 + 9 (8 x) + 9 \cdot - 9$

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

Move $x$ .

$8 \cdot 8 (x \cdot x) + 8 x \cdot - 9 + 9 (8 x) + 9 \cdot - 9$

Multiply $x$ by $x$ .

$8 \cdot 8 x^{2} + 8 x \cdot - 9 + 9 (8 x) + 9 \cdot - 9$

Multiply $8$ by $8$ .

$64 x^{2} + 8 x \cdot - 9 + 9 (8 x) + 9 \cdot - 9$

Multiply $- 9$ by $8$ .

$64 x^{2} - 72 x + 9 (8 x) + 9 \cdot - 9$

Multiply $8$ by $9$ .

$64 x^{2} - 72 x + 72 x + 9 \cdot - 9$

Multiply $9$ by $- 9$ .

$64 x^{2} - 72 x + 72 x - 81$

Add $- 72 x$ and $72 x$ .

$64 x^{2} + 0 - 81$

Add $64 x^{2}$ and $0$ .

$64 x^{2} - 81$