Calculate square root of 14 + 6√5
Explanation:
Square root of 14 + 6√5 will be of the form √x + √y.
∴ (√x + √y)2 = 14 + 6√5
⇒ x + y + 2√xy = 14 + 6√5
Now, rational part of RHS = rational part on LHS ⇒ x + y = 14 …(1)
Also, irrational part of RHS = irrational part on LHS ⇒ 2√xy = 6√5 ⇒ xy = 45 …(2)
Solving (1) and (2), we get x = 9 and y = 5 or x = 5 and y = 9.
In both cases square root of 14 + 6√5 = 3 + √5
Hence, option (c).
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