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If (x - (1)/(x)) = 5, find the value of ...

If `(x - (1)/(x)) = 5`, find the value of `(x^(2) + (1)/(x^(2)))`

A

34

B

42

C

27

D

63

Text Solution

AI Generated Solution

The correct Answer is:
To solve the equation \( x - \frac{1}{x} = 5 \) and find the value of \( x^2 + \frac{1}{x^2} \), we can follow these steps: ### Step 1: Square both sides of the equation Starting with the equation: \[ x - \frac{1}{x} = 5 \] We square both sides: \[ \left( x - \frac{1}{x} \right)^2 = 5^2 \] ### Step 2: Expand the left-hand side Using the identity \( (a - b)^2 = a^2 - 2ab + b^2 \): \[ x^2 - 2 \cdot x \cdot \frac{1}{x} + \left( \frac{1}{x} \right)^2 = 25 \] This simplifies to: \[ x^2 - 2 + \frac{1}{x^2} = 25 \] ### Step 3: Combine like terms Rearranging the equation gives: \[ x^2 + \frac{1}{x^2} - 2 = 25 \] ### Step 4: Isolate \( x^2 + \frac{1}{x^2} \) Adding 2 to both sides: \[ x^2 + \frac{1}{x^2} = 25 + 2 \] ### Step 5: Calculate the final result Thus, we find: \[ x^2 + \frac{1}{x^2} = 27 \] ### Final Answer The value of \( x^2 + \frac{1}{x^2} \) is \( \boxed{27} \).
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