Answer
See answer below
Work Step by Step
Let $V$ be a vector space of problem 14.
Assume the set $S=\{(1,2);(3,8)\}$
Since $(1,2)=(1,2^1) \\
(3,8)=(3,2^3)
\rightarrow S \subset V$
By problem 14 we have $(0,1)$ is the zero vector of $V$.
Take $-3(1,2)+1(3,8)=(-3, 2^{-3})+(3,2^3)=(0,1)$
Hence, $S$ is a subspace of the vector space $V$ given in problem 14