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If X + I Y = 3 + 5 I 7 − 6 I , Then Y =

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Question

If \[x + iy = \frac{3 + 5i}{7 - 6i},\]  then y =

Options

  • 9/85

  •  −9/85

  •  53/85

  • none of these

MCQ
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Solution

\[\frac{53}{85}\]

\[x + iy=\frac{3 + 5i}{7 - 6i}\]

\[\Rightarrow x+iy=\frac{3 + 5i}{7 - 6i}\times\frac{7 + 6i}{7 + 6i}\]

\[ \Rightarrow x+iy=\frac{21 + 53i + 30 i^2}{49 - 36 i^2}\]

\[ \Rightarrow x+iy=\frac{21 - 30 + 53i}{49 + 36}\]

\[ \Rightarrow x+iy=\frac{- 9}{85}+ i\frac{53}{85}\]

\[\text { On comparing both the sdes: } \]

\[y=\frac{53}{85}\]

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Chapter 13: Complex Numbers - Exercise 13.6 [Page 65]

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R.D. Sharma Mathematics [English] Class 11
Chapter 13 Complex Numbers
Exercise 13.6 | Q 26 | Page 65

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