Subjects algebra

Complex Multiplication 3C5682

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Question: Write the following expression as a single complex number. $$(3 - 2i)(4 + 2i)$$ Options: $16 - 2i$ $16 + 2i$ $12 - 4i$ $12 + 4i$
1. **State the problem:** We need to multiply the complex numbers $3 - 2i$ and $4 + 2i$ and write the result as a single complex number. 2. **Recall the formula:** To multiply two complex numbers $(a + bi)(c + di)$, use the distributive property: $$ (a + bi)(c + di) = ac + adi + bci + bdi^2 $$ Remember that $i^2 = -1$. 3. **Apply the formula:** $$ (3 - 2i)(4 + 2i) = 3 \times 4 + 3 \times 2i - 2i \times 4 - 2i \times 2i $$ $$ = 12 + 6i - 8i - 4i^2 $$ 4. **Simplify the imaginary terms:** $$ 6i - 8i = -2i $$ 5. **Simplify the $i^2$ term:** Since $i^2 = -1$, $$ -4i^2 = -4 \times (-1) = 4 $$ 6. **Combine all terms:** $$ 12 - 2i + 4 = (12 + 4) - 2i = 16 - 2i $$ 7. **Final answer:** The product is $$16 - 2i$$. Therefore, the correct choice is **$16 - 2i$**.