Simplify (4-3i)(4+3i)

$(4 - 3 i) (4 + 3 i)$

Expand $(4 - 3 i) (4 + 3 i)$ using the FOIL Method.

Apply the distributive property.

$4 (4 + 3 i) - 3 i (4 + 3 i)$

Apply the distributive property.

$4 \cdot 4 + 4 (3 i) - 3 i (4 + 3 i)$

Apply the distributive property.

$4 \cdot 4 + 4 (3 i) - 3 i \cdot 4 - 3 i (3 i)$

Simplify and combine like terms.

Simplify each term.

Multiply $4$ by $4$ .

$16 + 4 (3 i) - 3 i \cdot 4 - 3 i (3 i)$

Multiply $3$ by $4$ .

$16 + 12 i - 3 i \cdot 4 - 3 i (3 i)$

Multiply $4$ by $- 3$ .

$16 + 12 i - 12 i - 3 i (3 i)$

Multiply $- 3 i (3 i)$ .

Multiply $3$ by $- 3$ .

$16 + 12 i - 12 i - 9 i i$

Raise $i$ to the power of $1$ .

$16 + 12 i - 12 i - 9 (i^{1} i)$

Raise $i$ to the power of $1$ .

$16 + 12 i - 12 i - 9 (i^{1} i^{1})$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$16 + 12 i - 12 i - 9 i^{1 + 1}$

Add $1$ and $1$ .

$16 + 12 i - 12 i - 9 i^{2}$

Rewrite $i^{2}$ as $- 1$ .

$16 + 12 i - 12 i - 9 \cdot - 1$

Multiply $- 9$ by $- 1$ .

$16 + 12 i - 12 i + 9$

Add $16$ and $9$ .

$25 + 12 i - 12 i$

Subtract $12 i$ from $12 i$ .

$25 + 0$

Add $25$ and $0$ .

$25$