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# Write the expression as a complex number in standard form?

1) 8/1+i

2) 2+ 5i/5+2i

### 3 Answers

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- Wile E.Lv 78 years agoFavorite Answer
1.) 8 / (1 + i)

[8 / (1 + i)] [(1 - i) / (1 - i)]

8(1 - i) / [1 - (- 1)]

8(1- i) / (1 + 1)

8(1 - i) / 2

4(1 - i)

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2. (2 + 5i) / (5 + 2i)

[(2 + 5i) / (5 + 2i)] [(5 - 2i) / (5 - 2i)]

[10 - 4i + 25i - 10(- 1)] / [25 - 4(- 1)]

(10 + 21i + 10) / (25 + 4)

(20 + 21i) / 29

20/29 + 21/29 i

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Source(s): 11/28/12 - 8 years ago
Answer:

1. 4-4i

2. 20/29 + 21/29 i

Explanation:

You need to make the denominator a real number. You do this by multiplying the top and bottom of the fraction by the conjugate of the denominator. For the first one, the denominator is 1+i and the conjugate is 1-i. YOu multiply the top and bottom by this number.

Similarly for the second one, the denominator is 5+2i and the conjugate is 5-2i. Multiply the numerator and denominator by 5-2i.

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