Answer
$$[x]_S=\left[ \begin {array}{ccc} 5\\ 3\end {array} \right].$$
Work Step by Step
Since we have
$$x= (2,0)+ (3,3)=(5,3).$$
then we can write $x$ relative to the standard basis of $R^2$ as follows
$$x= (5,3)=5(1,0)+3(0,1) .$$
Thus, he coordinates matrix of $x$ in $R^2$ relative to the
standard basis is
$$[x]_S=\left[ \begin {array}{ccc} 5\\ 3\end {array} \right].$$