There exists a real number k such that the equation \(\begin{pmatrix} -3 \\ \phantom -0 \end{pmatrix} + t \begin{pmatrix} -4 \\ \phantom -1 \end{pmatrix} = \begin{pmatrix} -4 \\ \phantom -k \end{pmatrix} + s \begin{pmatrix} \phantom -8 \\ -2 \end{pmatrix}\)
has infinitely many solutions in t and s. Find k.
