136- For which value of $a$, the asymptote $x = \dfrac{21}{8}$ of the conic $2y^2 - 12y + ax + 8 = 0$ holds? (1) $12$ and $3$ (2) $16$ and $3$ (3) $12$ and $5$ (4) $16$ and $5$
\textbf{136-} For which value of $a$, the asymptote $x = \dfrac{21}{8}$ of the conic $2y^2 - 12y + ax + 8 = 0$ holds?
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(1) $12$ and $3$ \hfill (2) $16$ and $3$ \hfill (3) $12$ and $5$ \hfill (4) $16$ and $5$
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