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

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

Step 1

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

Apply the distributive property.

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

Apply the distributive property.

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

Apply the distributive property.

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

Step 2

Simplify and combine like terms.

Simplify each term.

Rewrite using the commutative property of multiplication.

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

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

Move $b$ .

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

Multiply $b$ by $b$ .

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

Multiply $4$ by $4$ .

$16 b^{2} + 4 b \cdot - 5 + 5 (4 b) + 5 \cdot - 5$

Multiply $- 5$ by $4$ .

$16 b^{2} - 20 b + 5 (4 b) + 5 \cdot - 5$

Multiply $4$ by $5$ .

$16 b^{2} - 20 b + 20 b + 5 \cdot - 5$

Multiply $5$ by $- 5$ .

$16 b^{2} - 20 b + 20 b - 25$

Add $- 20 b$ and $20 b$ .

$16 b^{2} + 0 - 25$

Add $16 b^{2}$ and $0$ .

$16 b^{2} - 25$