SSC Sample Paper SSC CHSL (10+2) Sample Test Paper-9

  • question_answer
    If \[x-\frac{1}{x}=1\], then the value of \[\frac{{{x}^{4}}-\frac{1}{{{x}^{2}}}}{3{{x}^{2}}+5x-3}\] is

    A) \[\frac{1}{4}\]              

    B)        \[\frac{1}{2}\]

    C) \[\frac{3}{4}\]                          

    D) 0

    Correct Answer: B

    Solution :

    Expression \[=\frac{{{x}^{4}}-\frac{1}{{{x}^{2}}}}{3{{x}^{2}}+5x-3}\] Dividing numerator and donator by \[x\], \[=\frac{{{x}^{3}}-\frac{1}{{{x}^{3}}}}{3x+5-\frac{3}{x}}=\frac{{{x}^{3}}-\frac{1}{{{x}^{3}}}}{3\left( x-\frac{1}{x} \right)+5}\] \[=\frac{{{\left( x-\frac{1}{x} \right)}^{3}}+3\left( x-\frac{1}{x} \right)}{3\left( x-\frac{1}{x} \right)+5}\] \[=\frac{1+3}{3+5}=\frac{4}{8}=\frac{1}{2}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner