[tex]\bf \begin{array}{lllll}
&x_1&y_1\\
% (a,b)
&({{ 1}}\quad ,&{{ 3}})\quad
\end{array}
\\\\\\
% slope = m
slope = {{ m}}= \cfrac{rise}{run} \implies 2
\\\\\\
% point-slope intercept
y-{{ y_1}}={{ m}}(x-{{ x_1}})\implies y-3=2(x-1)\\
\left. \qquad \right. \uparrow\\
\textit{point-slope form}[/tex]
