Q124 / 200 · TS EAMCET 2001 · Mathematics
If $\frac{x-4}{x^2-5 x-2 k}=\frac{2}{x-2}-\frac{1}{x+k^{\prime}}$, then $k$ is equal to
- Correct answerA$-3$
- B$-2$
- C$2$
- D$3$
Solution
We have,
$\begin{aligned} \frac{x-4}{x^2-5 x-2 k} & =\frac{2}{x-2}-\frac{1}{x+k} \\ \Rightarrow \quad \frac{x-4}{x^2-5 x-2 k} & =\frac{2(x+k)-(x-2)}{(x-2)(x+k)} \\ & =\frac{x+2 k+2}{(x-2)(x+k)}\end{aligned}$
On equating, we get
$\begin{aligned}-4 & =2 k+2 \\ 2 k & =-6 \Rightarrow k=-3\end{aligned}$
Hence, the correct answer is option: 'A'.