\( \definecolor{colordef}{RGB}{249,49,84} \definecolor{colorprop}{RGB}{18,102,241} \)
Calculate the product of the vector \(\vec{b} = \begin{pmatrix} -5 \\ 4 \end{pmatrix}\) by \(3\).
\(3\vec{b} =\begin{pmatrix} \input{124570}{}{3em}{2em}{}{}\\ \input{224570}{}{3em}{2em}{}{}\\ \end{pmatrix} \)