Should one write a line in a matrix when solving systems of linear equations?

Question

Should one write a line in a matrix when solving systems of linear equations?

For example, consider the system consisting of $ax+by=c$ and $dx+ey=f$, should one write $$\left( \begin{array}{ccc} a & b & c \\ d & e & f \end{array} \right) \quad \mathrm{or} \quad \left( \begin{array}{cc|c} a & b & c \\ d & e & f \end{array} \right)$$

Which one is perferred?

Answer 1

The comments tell us that

• The second notation is generally preferred,
• The line informs that it is an augmented matrix.