If A2 + B2 = 29 and Ab = 10, Find : a + B

If a² + b² = 29 and ab = 10, find : a + b

Sum

(a + b)² = a² + b²+ 2ab

⇒ (a + b)² = 29 + 2×10

⇒ (a + b)² = 29 + 20

⇒ (a + b)² = 49

⇒ a + b = `sqrt49`

⇒ a + b = ±7

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Application of Formulae

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Chapter 12: Identities - Exercise 12 (C) [Page 154]

Chapter 12 Identities
Exercise 12 (C) | Q 3.1 | Page 154

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