[Tex/LaTex] Matrices Representation of Linear Equation AX=B

Question

Hi I am new To Latex and trying To write a paper. Please provide me with how to write in latex for below matrix ?

I was only able to do this:

\[
\begin{bmatrix}
x_{11}       & x_{12} & x_{13} & \dots & x_{1n} \\
x_{21}       & x_{22} & x_{23} & \dots & x_{2n} \\
\hdotsfor{5} 
x_{d1}       & x_{d2} & x_{d3} & \dots & x_{dn}
\end{bmatrix}
\]

Answer 1

Echoing the sentiment expressed by @PrzemysławScherwentke, I also hope that you're not looking to reproduce exactly the rather uninspired look of the matrices shown in the screenshot.

\documentclass{article}
\usepackage{amsmath} % for 'bmatrix' environment
\usepackage{newtxtext,newtxmath} % optional -- Times Roman clone
\begin{document}
\[
\begin{bmatrix}
a_{11} & a_{12} & a_{13} & \dots & a_{1n} \\
a_{21} & a_{22} & a_{23} & \dots & a_{2n} \\
\dots  & \dots  & \dots  & \dots & \dots  \\
a_{n1} & a_{n2} & a_{n3} & \dots & a_{nn} 
\end{bmatrix}
\begin{bmatrix}
x_1 \\ x_2 \\ \dots \\ x_n 
\end{bmatrix}
=
\begin{bmatrix}
a_{1,n+1} \\ a_{2,n+1} \\ \dots \\ a_{n,n+1}
\end{bmatrix}
\]

\medskip

\[
\setlength\arrayrulewidth{0.6pt} % default value: 0.4pt
\left[ \mkern1mu \begin{array}{@{}ccccc|c@{}}
a_{11} & a_{12} & a_{13} & \dots & a_{1n} & a_{1,n+1} \\
a_{21} & a_{22} & a_{23} & \dots & a_{2n} & a_{2,n+1} \\
\dots  & \dots  & \dots  & \dots & \dots  & \dots \\
a_{n1} & a_{n2} & a_{n3} & \dots & a_{nn} & a_{n,n+1} 
\end{array} \mkern1mu \right]
\]
\end{document}