[tex]\bf \begin{array}{lllll}
&x_1&y_1\\
% (a,b)
&({{ d}}\quad ,&{{ d}})\quad
\end{array}
\\\\\\
% slope = m
slope = {{ m}}= \cfrac{rise}{run} \implies k
\\\\\\
% point-slope intercept
\stackrel{\textit{point-slope form}}{y-{{ y_1}}={{ m}}(x-{{ x_1}})}\implies y-d=k(x-d)\implies y-d=kx-kd
\\\\\\
y=kx-kd+d[/tex]
