Hello, I am having a hard time figuring this out.

Let's say A is a matrix that projects vectors onto \(\begin{pmatrix}1 \\ 3 \end{pmatrix}\).

What is matrix A?

Any help is appreciated.

Thank you in advance!!!

The projection matrix is

\(\begin{pmatrix} 1/10 & 3/10 \\ 1/30 & 1/10 \end{pmatrix}\)