Problem:
Are the vectors \( \overrightarrow{c_{1}} \) and \( \overrightarrow{c_{2}} \), formed by the vectors \( \vec{a} \) and \( \vec{b} \) collinear?
\[
\begin{array}{ll}
\vec{a}=\{-1 ; 2 ;-1\}, & \vec{b}=\{2 ;-7 ; 1\}, \\
\overrightarrow{c_{1}}=6 \vec{a}-2 \vec{b}, & \overrightarrow{c_{2}}=\vec{b}-3 \vec{a} .
\end{array}
\]