[tex]\bf \begin{array}{lllll}
&x_1&y_1\\
% (a,b)
&({{ -9}}\quad ,&{{ -3}})
\end{array}
\\\\\\
% slope = m
slope = {{ m}}= \cfrac{rise}{run} \implies -6
\\\\\\
% point-slope intercept
\stackrel{\textit{point-slope form}}{y-{{ y_1}}={{ m}}(x-{{ x_1}})}\implies y-(-3)=-6[x-(-9)]
\\\\\\
y+3=-6(x+9)\implies y+3=-6x-54\implies y=-6x-57[/tex]
