Simplify (5b+4)(5b-4)

$(5 b + 4) (5 b - 4)$

Step 1

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

Apply the distributive property.

$5 b (5 b - 4) + 4 (5 b - 4)$

Apply the distributive property.

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

Apply the distributive property.

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

Step 2

Simplify terms.

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

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

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

Add $- 4 \cdot 5 b$ and $4 \cdot 5 b$ .

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

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

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

Simplify each term.

Rewrite using the commutative property of multiplication.

$5 \cdot 5 b \cdot b + 4 \cdot - 4$

Multiply $b$ by $b$ by adding the exponents.

Move $b$ .

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

Multiply $b$ by $b$ .

$5 \cdot 5 b^{2} + 4 \cdot - 4$

Multiply $5$ by $5$ .

$25 b^{2} + 4 \cdot - 4$

Multiply $4$ by $- 4$ .

$25 b^{2} - 16$