[tex]\bf \begin{cases}
u=\ \textless \ -5,-3\ \textgreater \ \\
v=\ \textless \ -6,-1\ \textgreater \
\end{cases}
\\\\\\
\begin{cases}
-3u\implies \ \textless \ -3\cdot -5~~,~~-3\cdot -3\ \textgreater \ \implies &\ \textless \ 15,9\ \textgreater \
\\\\\\
5v\implies \ \textless \ 5\cdot -6~~,~~5\cdot -1\ \textgreater \ \implies &\ \textless \ -30,-5\ \textgreater \
\end{cases}\\\\
-------------------------------\\\\
-3u+5v\implies \ \textless \ 15,9\ \textgreater \ ~~+~~\ \textless \ -30,-5\ \textgreater \
\\\\\\
\ \textless \ 15+(-30)~~,~~9+(-5)\ \textgreater \ \implies \ \textless \ -25~~,~~4\ \textgreater \ [/tex]
notice, you simply do the "scalar multiplication" first, and then do the addition.
