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Question
If `x + 1/x = 3, "then" x^2 + 1/x^2` = ______.
Options
9
7
11
12
MCQ
Fill in the Blanks
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Solution
If `x + 1/x = 3, "then" x^2 + 1/x^2` = 7.
Explanation:
`x + 1/x = 3,`
Squaring both sides:
`x^2 + 1/x^2 = (x + 1/x)^2 - 2`
`x^2 + 1/x^2 = (3)^2 - 2`
`x^2 + 1/x^2 = 9-2`
`x^2 + 1/x^2 = 7`
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Number System (Entrance Exam)
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