2.
已知向量\( \overrightarrow{a}=(1,2)\),\( \overrightarrow{b}=(2,λ)\),\( \overrightarrow{c}=(-3,2)\).
\((1)\)若\( \overrightarrow{a}/\!/ \overrightarrow{b}\),求实数\(λ\)的值;
\((2)\)若\(k \overrightarrow{a}+ \overrightarrow{c}\)与\( \overrightarrow{a}-2 \overrightarrow{c}\)垂直,求实数\(k\)的值.