Mathjax test

$$a^2+b^2=c^2 \tag {1.1}$$

\begin{matrix} (1.1) & a^{2} + b^{2} = c^{2} \end{matrix}

The tag of the above equation is $1.1$

$$
\begin{split}
a &= b \\
c &= d \\
e &= f
\end{split}\tag{1.2}
$$

\begin{matrix} (1.2) & \begin{aligned} a & = b \\ c & = d \\ e & = f \end{aligned} \end{matrix}

This should render 3 lines, but may only render the 3 equations in just 1 line.
Try the following code:

$$
\begin{split}
a &= b \newline
c &= d \newline
e &= f
\end{split}\tag{1.3}
$$

\begin{matrix} (1.3) & \begin{aligned} a & = b \\ c & = d \\ e & = f \end{aligned} \end{matrix}

$$
\begin{eqnarray*}
x^n+y^n &=& z^n \tag{1.4} \newline
x+y &=& z \tag{1.5}
\end{eqnarray*}
$$

\begin{array}{rcl} (1.4) & x^{n} + y^{n} & = & z^{n} \\ (1.5) & x + y & = & z \end{array}

$$
\begin{eqnarray*}
x^n+y^n &=& z^n \tag{1.4} \newline
x+y &=& z \tag{1.5}
\end{eqnarray*}
$$

\begin{matrix} (1.6) & (\begin{matrix} a_{1}, & a_{2}, & \dots, & a_{3} \\ a_{2}, & a_{4}, & \dots, & a_{5} \\ ⋮, & ⋮, & \dots, & \dots \\ a_{m}, & a_{m + 1}, & \dots, & a_{m n} \end{matrix}) \end{matrix}