2000019101
Level:
B
Determine the set of all values of the parameter \( a \in \mathbb{R} \setminus \{0\}\) for which the given equation has no solution.
\[
\frac{x-1}{x} = \frac{2-a}{3a}
\]
\(\left\{ \frac12\right\}\)
\(\left\{ \frac12; 2\right\}\)
\( \{ 1 \}\)
\(\left\{ \frac12; 1\right\}\)