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Question
Simplify : `4sqrt(-4) + 5sqrt(-9) - 3sqrt(-16)`
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Solution
`4sqrt(-4) + 5sqrt(-9) - 3sqrt(-16)`
`= 4sqrt(4 xx -1) + 5sqrt(9 xx -1) - 3sqrt(16 xx - 1)`
= 4 × 2i + 5 × 3i – 3 × 4i
= 8i + 15i – 12i
= (8 + 15 – 12)i
= 11i
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