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Write the following numbers in a + bi form: (a) \( \frac{-2 + i}{3 + 4i} \) = \( \_\_\_ \) + \( \_\_\_ \)i....

Write the following numbers in a + bi form:
(a) \( \frac{-2 + i}{3 + 4i} \) = \( \_\_\_ \) + \( \_\_\_ \)i.
(b) \( \frac{3}{4i} + \frac{2}{2i} \) = \( \_\_\_ \) + \( \_\_\_ \)i.
(c) \( (i)^3 \) = \( \_\_\_ \) + \( \_\_\_ \)i.

Answer

  1. To simplify \( \frac{-2 + i}{3 + 4i} \), multiply numerator and denominator by the conjugate of the denominator: \( 3 - 4i \).
    \[ \frac{(-2 + i)(3 - 4i)}{(3 + 4i)(3 - 4i)} = \frac{-6 + 8i + 3i - 4i^2}{9 + 16} = \frac{-6 + 11i + 4}{25} = \frac{-2 + 11i}{25} \]
    \[ = -\frac{2}{25} + \frac{11}{25}i \]

  2. To simplify \( \frac{3}{4i} + \frac{2}{2i} \), rewrite each term:
    \[ \frac{3}{4i} = \frac{3}{4i} \times \frac{-i}{-i} = -\frac{3i}{4i^2} = \frac{3i}{4} \] (since \( i^2 = -1 \))
    \[ \frac{2}{2i} = \frac{2}{2i} \times \frac{-i}{-i} = -\frac{2i}{2i^2} = i \]
    Combine the terms: \( \frac{3}{4} + i \)

  3. \( (i)^3 = i^2 \cdot i = (-1) \cdot i = -i \)
    \[ = 0 - i \]

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