CAT 2020 Quant Question [Slot 3] with Solution 04

Simultaneous equation have a unique solution only if \(\frac{{{a_1}}}{{{a_2}}} \ne \frac{{{b_1}}}{{{b_2}}}\)

From the given equations, a unique solution would exist only if \(\frac{k}{2} \ne \frac{2}{k}\)

\( \Rightarrow {k^2} \ne 4 \Rightarrow |k| \ne 2\)