J & K CET Engineering J and K - CET Engineering Solved Paper-2004

  • question_answer
    If \[{{a}_{1}},{{a}_{2}}{{a}_{3}},{{a}_{4}},{{a}_{5}},{{a}_{6}}\] are in, AP with common difference \[d\ne 0,\] .then the system of equations \[{{a}_{1}}x+{{a}_{2}}y={{a}_{3}},{{a}_{4}}x+{{a}_{5}}y={{a}_{6}}\]has

    A)  infinite number of solutions

    B)  unique solution

    C)  no solution

    D)  cannot say anything

    Correct Answer: B

    Solution :

    Let \[\Delta =\left| \begin{matrix}    {{a}_{1}} & {{a}_{2}}  \\    {{a}_{4}} & {{a}_{5}}  \\ \end{matrix} \right|\] \[={{a}_{1}}{{a}_{5}}-{{a}_{2}}{{a}_{4}}\] \[={{a}_{1}}({{a}_{1}}+4d)-({{a}_{1}}+d)\,({{a}_{1}}+3d)\] \[=a_{1}^{2}+4{{a}_{1}}d-a_{1}^{2}-4{{a}_{1}}d-3{{d}^{2}}\] \[=-3{{d}^{2}}\ne 0\] Hence, given system of equations has unique solution.


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