Simplify (5x-4)(5x+4)

$(5 x - 4) (5 x + 4)$

Step 1

Expand $(5 x - 4) (5 x + 4)$ using the FOIL Method.

Apply the distributive property.

$5 x (5 x + 4) - 4 (5 x + 4)$

Apply the distributive property.

$5 x (5 x) + 5 x \cdot 4 - 4 (5 x + 4)$

Apply the distributive property.

$5 x (5 x) + 5 x \cdot 4 - 4 (5 x) - 4 \cdot 4$

Step 2

Simplify terms.

Combine the opposite terms in $5 x (5 x) + 5 x \cdot 4 - 4 (5 x) - 4 \cdot 4$ .

Reorder the factors in the terms $5 x \cdot 4$ and $- 4 (5 x)$ .

$5 x (5 x) + 4 \cdot 5 x - 4 \cdot 5 x - 4 \cdot 4$

Subtract $4 \cdot 5 x$ from $4 \cdot 5 x$ .

$5 x (5 x) + 0 - 4 \cdot 4$

Add $5 x (5 x)$ and $0$ .

$5 x (5 x) - 4 \cdot 4$

Simplify each term.

Rewrite using the commutative property of multiplication.

$5 \cdot 5 x \cdot x - 4 \cdot 4$

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

Move $x$ .

$5 \cdot 5 (x \cdot x) - 4 \cdot 4$

Multiply $x$ by $x$ .

$5 \cdot 5 x^{2} - 4 \cdot 4$

Multiply $5$ by $5$ .

$25 x^{2} - 4 \cdot 4$

Multiply $- 4$ by $4$ .

$25 x^{2} - 16$