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Simplify the expression:

3 - 4i
1 - 2i

A. 3 + 2i
B. 5/3 + 2/3i
C. 5/3 - 2/3i
D. 11/5 - 2/5i

1 Answer

1 vote

Final answer:

The expression 3 - 4i / 1 - 2i, when simplified by multiplying both numerator and denominator by the complex conjugate of the denominator, yields a result of (11/5) - (2/5)i, which corresponds to option D.

Step-by-step explanation:

To simplify the expression 3 - 4i / 1 - 2i, we must multiply both the numerator and the denominator by the complex conjugate of the denominator to remove the imaginary unit i from the denominator. The complex conjugate of 1 - 2i is 1 + 2i. By multiplying the numerator and denominator by this complex conjugate, we get:

(3 - 4i)(1 + 2i) / (1 - 2i)(1 + 2i)

This simplifies to:

(3 + 6i - 4i - 8i²) / (1 + 2i - 2i - 4i²)

Since i² = -1, we can further simplify this to:

(3 + 2i + 8) / (1 + 4)

Which simplifies to:

(11 + 2i) / 5

Dividing both terms in the numerator by 5 gives us the answer:

(11/5) + (2/5)i

Therefore, the simplified expression is option D: 11/5 - 2/5i.

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