EduGoog

If (x + 1/x) = 3, then (x21/x2) is equal to :

Option:
A. 10 / 3
B. 82 / 9
C. 7
D. 11
Answer: C . 7

Justification:

x + 1/x = 3

→ (x + 1/x)2 = 9

→ x2 + 1/x2 + 2 = 9

→ x21/x2 = 7.

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