A) 125
B) 130
C) 135
D) 140
Correct Answer: D
Solution :
\[x-\frac{1}{x}=5\] or \[{{\left( x-\frac{1}{x} \right)}^{3}}={{5}^{3}}\] or \[{{x}^{3}}-\frac{1}{{{x}^{3}}}-3x\frac{1}{x}\left( x-\frac{1}{x} \right)=125\] or \[{{x}^{3}}-\frac{1}{{{x}^{3}}}-3\times 5=125\] or \[{{x}^{3}}-\frac{1}{{{x}^{3}}}=140\]You need to login to perform this action.
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