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Question
Write the value of \[\sqrt{- 25} \times \sqrt{- 9}\].
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Solution
\[\sqrt{- 25} \times \sqrt{- 9} = 5\sqrt{- 1} \times 3\sqrt{- 1}\]
\[ = 5i \times 3i\]
\[ = 15 i^2 \]
\[ = - 15\]
Hence,
\[\sqrt{- 25} \times \sqrt{- 9} = - 15\]
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