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Question
If a2 + b2= 10 and ab = 3; find : a + b
Sum
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Solution
(a + b)2 = a2 + b2 + 2ab
⇒ (a + b)2 = 10 + 2×3
⇒ (a + b)2 = 10 + 6
⇒ (a + b)2 = 16
⇒ (a + b) = `sqrt16`
⇒ a + b = ±4
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