Simplify (a+4)(a-4)

$(a + 4) (a - 4)$

Step 1

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

Apply the distributive property.

$a (a - 4) + 4 (a - 4)$

Apply the distributive property.

$a \cdot a + a \cdot - 4 + 4 (a - 4)$

Apply the distributive property.

$a \cdot a + a \cdot - 4 + 4 a + 4 \cdot - 4$

Step 2

Simplify terms.

Combine the opposite terms in $a \cdot a + a \cdot - 4 + 4 a + 4 \cdot - 4$ .

Reorder the factors in the terms $a \cdot - 4$ and $4 a$ .

$a \cdot a - 4 a + 4 a + 4 \cdot - 4$

Add $- 4 a$ and $4 a$ .

$a \cdot a + 0 + 4 \cdot - 4$

Add $a \cdot a$ and $0$ .

$a \cdot a + 4 \cdot - 4$

Simplify each term.

Multiply $a$ by $a$ .

$a^{2} + 4 \cdot - 4$

Multiply $4$ by $- 4$ .

$a^{2} - 16$