Đáp án:
Chọn D.
Giải thích các bước giải:
\[\begin{array}{l}
\overrightarrow a = \left( {1;\,\,3} \right);\,\,\,\overrightarrow b = \left( { - 3;\,\,0} \right);\,\,\,\overrightarrow c = \left( { - 1;\,\,2} \right)\\
Ta\,\,dat:\,\,\overrightarrow c = m\overrightarrow a + n\overrightarrow b \,\,\,\left( {m,\,\,n \in R} \right)\\
\Rightarrow \left( { - 1;\,\,2} \right) = m\left( {1;\,\,3} \right) + n\left( { - 3;\,\,0} \right)\\
\Leftrightarrow \left( { - 1;\,\,2} \right) = \left( {m - 3n;\,\,3m} \right)\\
\Leftrightarrow \left\{ \begin{array}{l}
- 1 = m - 3n\\
2 = 3m
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
m = \frac{2}{3}\\
n = \frac{5}{9}
\end{array} \right. \Rightarrow \overrightarrow c = \frac{2}{3}\overrightarrow a + \frac{5}{9}\overrightarrow b .
\end{array}\]
