Ans:
$k x(x-2)+6=0$ $\Rightarrow k x^{2}-2 k x+6=0$ Comparing quadratic equation $k x^{2}-2 k x+6=0$ with general form $a x^{2}+b x+c=0$
, we get $\mathrm{a}=\mathrm{k}, \mathrm{b}=-2 \mathrm{k}$ and $\mathrm{c}=6$
Discriminant $=\mathrm{b}^{2}-4 \mathrm{ac}=(-2 \mathrm{k})^{2}-4(\mathrm{k})(6)=4 \mathrm{k}^{2}-24 \mathrm{k}$
We know that two roots of quadratic equation are equal only if discriminant is equal to zero.
Putting discriminant equal to zero
$$
\begin{array}{l}
4 k^{2}-24 k=0 \\
\Rightarrow 4 k(k-6)=0 \\
\Rightarrow k=0,6
\end{array}
$$
The basic definition of quadratic equation says that quadratic equation is the equation of the form $a x^{2}+b x+c=0$, where $a \neq 0$.
Therefore, in equation $k x^{2}-2 k x+6=0$, we cannot have $k=0$.
Therefore, we discard $k=0$
Hence the answer is $\mathrm{k}=6$