[tex]\bf (\stackrel{x_1}{3}~,~\stackrel{y_1}{5})~\hspace{10em} slope = m\implies -1 \\\\\\ \begin{array}{|c|ll} \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-5=-1(x-3) \\\\\\ y-5=-x+3\implies y=-x+8[/tex]