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Select the correct form of -2i (9-31) - (6-10i) written as a complex number in standard form.

a. -20 - 38i
b. 20 + 38i
c. -20 + 38i
d. 20 - 38i

1 Answer

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Final answer:

After distributing -2i to each term within the parentheses and then subtracting the second complex number, the answer should be 56 - 8i, which is not an option listed. There appears to be an error with the provided choices.

Step-by-step explanation:

The question asks to simplify the expression -2i (9-31i) - (6-10i) and write the result as a complex number in standard form, which is a + bi, where a is the real part and bi is the imaginary part.

First, distribute -2i to both terms in the parenthesis (9 - 31i):

  • -2i × 9 = -18i
  • -2i × (-31i) = 62

Next, subtract the second complex number (6 - 10i) from the result:

  • 62 - 6 = 56
  • -18i - (-10i) = -8i

Combining the real and imaginary components, we get 56 - 8i, which is not an option in the multiple-choice list provided. It seems there is an error either in the question or the options given. However, the process described here is correct for combining complex numbers.

User Joebobfrank
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