If a2 + b2 = 234 and ab = 108, find the value of a + b

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If a² + b² = 234 and ab = 108, find the value of a + b / a - b . ?

1. 10
2. 8
3. 5
4. 4

Correct Option: C

We know that, (a + b)² = a² + b² + 2ab
= 234 + 2 x 108 = 450
(a - b)² = a² + b² - 2ab
= 234 - 2 x 108 = 18
∴ (a + b)²/(a - b)² = 450/18 = 25
⇒ [(a + b)/(a - b)]² = 25
∴ (a + b)/(a - b) = √25 = 5