Correct Answer - Option 1 : x = 2
\(\left[ {\begin{array}{*{20}{c}} x&1 \end{array}} \right]\left[ {\begin{array}{*{20}{c}} 1&0\\ { - 2}&0 \end{array}} \right] = 0\)
\(\Rightarrow \left[ {\begin{array}{*{20}{c}} {x - 2}&0 \end{array}} \right] = 0 = \left[ {\begin{array}{*{20}{c}} 0&0 \end{array}} \right]\)
As the two matrices are equal, their corresponding elements are also equal.
Comparing the corresponding elements:
x - 2 = 0 ⇒ x = 2