Simplify (3-4i)(2+i)

$(3 - 4 i) (2 + i)$

Step 1

Expand $(3 - 4 i) (2 + i)$ using the FOIL Method.

Apply the distributive property.

$3 (2 + i) - 4 i (2 + i)$

Apply the distributive property.

$3 \cdot 2 + 3 i - 4 i (2 + i)$

Apply the distributive property.

$3 \cdot 2 + 3 i - 4 i \cdot 2 - 4 i i$

$3 \cdot 2 + 3 i - 4 i \cdot 2 - 4 i i$

Step 2

Simplify and combine like terms.

Simplify each term.

Multiply $3$ by $2$ .

$6 + 3 i - 4 i \cdot 2 - 4 i i$

Multiply $2$ by $- 4$ .

$6 + 3 i - 8 i - 4 i i$

Multiply $- 4 i i$ .

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

$6 + 3 i - 8 i - 4 (i^{1} i)$

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

$6 + 3 i - 8 i - 4 (i^{1} i^{1})$

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

$6 + 3 i - 8 i - 4 i^{1 + 1}$

Add $1$ and $1$ .

$6 + 3 i - 8 i - 4 i^{2}$

$6 + 3 i - 8 i - 4 i^{2}$

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

$6 + 3 i - 8 i - 4 \cdot - 1$

Multiply $- 4$ by $- 1$ .

$6 + 3 i - 8 i + 4$

$6 + 3 i - 8 i + 4$

Add $6$ and $4$ .

$10 + 3 i - 8 i$

Subtract $8 i$ from $3 i$ .

$10 - 5 i$

$10 - 5 i$

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