Quantitative Aptitude Ques 2487
Question: If $ x+(1/x)=2, $ then the value of $ x^{7}+(1/x^{5}) $ is
Options:
A) $ 2^{5} $
B) $ 2^{12} $
C) 2
D) $ 2^{7} $
Show Answer
Answer:
Correct Answer: C
Solution:
- Given, $ x+\frac{1}{x}=2 $
$ \Rightarrow $ $ x^{2}+1=2x $
$ \Rightarrow $ $ x^{2}-2x+1=0 $
$ \Rightarrow $ $ {{(x-1)}^{2}}=0 $
$ \Rightarrow $ $ x-1=0\Rightarrow x=1 $
$ \therefore $ $ x^{7}+\frac{1}{x^{5}}={{(1)}^{7}}+\frac{1}{{{(1)}^{5}}}=1+\frac{1}{1}=1+1=2 $
BETA
