[tex]\bf \begin{array}{ccccccccc}
&&x_1&&y_1\\
% (a,b)
&&(~{{ -6}} &,&{{ 6}}~)
\end{array}
\\\\\\
% slope = m
slope = {{ m}}\implies -2
\\\\\\
% point-slope intercept
\stackrel{\textit{point-slope form}}{y-{{ y_1}}={{ m}}(x-{{ x_1}})}\implies y-6=-2[x-(-6)]
\\\\\\
y-6=-2(x+6)\implies y-6=-2x-12\implies y=-2x-6[/tex]
