I'm familiar with proving subspaces but am unsure over how to approach this question. I don't understand what the notation is implying about $S$ so any help would be greatly appreciated. Cheers.
Decide if set $S$ is a subspace of the given vector space $V$.
$V=\mathbb{R}^2 \; and\;S=\{w=(x,y)\in \mathbb{R}^2 |\; x\ge0\}.$
HINT
Let consider
and then consider the combination