You multiply vectors and scalar simply by multiplying each component by that scalar:
[tex]-7u = \langle-35,7\rangle,\quad -3v=\langle -3,-36\rangle[/tex]
Finally, you sum two vectors by summing the correspondent coordinates:
[tex]-7u-3v = \langle-35,7\rangle+\langle -3,-36\rangle = \langle-38,-29\rangle[/tex]