Here's a LyX file (including step by step instructions). Paul
#LyX 2.0 created this file. For more info see http://www.lyx.org/ \lyxformat 413 \begin_document \begin_header \textclass article \use_default_options true \maintain_unincluded_children false \language english \language_package default \inputencoding auto \fontencoding global \font_roman lmodern \font_sans lmss \font_typewriter lmtt \font_default_family default \use_non_tex_fonts false \font_sc false \font_osf false \font_sf_scale 100 \font_tt_scale 100 \graphics default \default_output_format default \output_sync 0 \bibtex_command default \index_command default \paperfontsize default \spacing single \use_hyperref false \papersize letterpaper \use_geometry true \use_amsmath 1 \use_esint 1 \use_mhchem 1 \use_mathdots 1 \cite_engine basic \use_bibtopic false \use_indices false \paperorientation portrait \suppress_date false \use_refstyle 0 \index Index \shortcut idx \color #008000 \end_index \leftmargin 1in \topmargin 1in \rightmargin 1in \bottommargin 1in \secnumdepth 3 \tocdepth 3 \paragraph_separation skip \defskip medskip \quotes_language english \papercolumns 1 \papersides 1 \paperpagestyle default \tracking_changes false \output_changes false \html_math_output 0 \html_css_as_file 0 \html_be_strict false \end_header \begin_body \begin_layout Standard \begin_inset Formula \[ \textrm{System: }\begin{aligned}2x-3y=8\\ 4x+5y=1 \end{aligned} \qquad\textrm{Augmented Matrix: }\left[\begin{array}{cc|c} 2 & -3 & 8\\ 4 & 5 & 1 \end{array}\right] \] \end_inset \end_layout \begin_layout Standard Construction: \end_layout \begin_layout Enumerate Insert > Math > Display Formula \end_layout \begin_layout Enumerate Type \backslash textrm (space) to create text insert \end_layout \begin_deeper \begin_layout Enumerate Type \begin_inset Quotes eld \end_inset System: \begin_inset Quotes erd \end_inset (including the space) \end_layout \begin_layout Enumerate Exit the text inset (staying inside the formula inset) using the cursor keys or mouse \end_layout \end_deeper \begin_layout Enumerate Type \backslash aligned (space) to create an aligned inset \end_layout \begin_deeper \begin_layout Enumerate Type the first equation and hit Ctrl-Enter to get a second line \end_layout \begin_layout Enumerate Type the second equation and exit the aligned inset using the arrow key, space key or mouse \end_layout \end_deeper \begin_layout Enumerate Type Ctrl-Space and add a few more spaces to separate the two parts \end_layout \begin_layout Enumerate Repeat step 2 using the text \begin_inset Quotes eld \end_inset Augmented Matrix: \begin_inset Quotes erd \end_inset \end_layout \begin_layout Enumerate Use Insert > Math > Delimiters to create the brackets for the matrix \end_layout \begin_layout Enumerate Use Insert > Math > Array Environment to create a 2x3 array \end_layout \begin_deeper \begin_layout Enumerate Enter the coefficients \end_layout \begin_layout Enumerate With the cursor in the last column (either row), click Edit > Math > Add Line to Left \end_layout \end_deeper \begin_layout Standard \end_layout \end_body \end_document
