2. Sample Papers
  3. KVPY

KVPY Sample Paper KVPY Stream-SX Model Paper-6

  • question_answer
    If the straight line \[x+2y=9,\]\[3x-5y=5\] & \[ax+by=1\] are concurrent, then the straight line \[5x+2y=1\] passes through the point:

    A) \[(a,\,\,-b)\]                    

    B) \[(-\,a,\,\,b)\]

    C) \[(a,\,\,b)\]                     

    D) \[(-\,a,\,\,-b)\]

    Correct Answer: C

    Solution :

    \[x+2y=9,\]       \[3x-5y=5,\]       \[ax+by=1\]
    are concurrent
    \[\left| \begin{matrix}    1 & 2 & -\,9  \\    3 & -\,5 & -\,5  \\    a & b & -1  \\ \end{matrix} \right|=0\]
    \[\Rightarrow \]   \[1\,(5+5b)+2\,(-\,5a+3)-9\,(3b+5a)=0\]
    \[\Rightarrow \]   \[-\,55a-22b+11=0\]\[\Rightarrow \]          \[5a+2b=1\]
    Hence line \[5x+2y=1\] passes through the point (a, b)


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