Let us find the slope first
[tex]\begin{gathered} m=\text{slope = }\frac{y_2-y_1}{x_2-x_1} \\ m=\frac{1-6}{0+5} \\ m=-\frac{5}{5}=-1 \end{gathered}[/tex]The equation can be found as follows using the points (0 ,1)
[tex]\begin{gathered} m=\frac{y-y_1}{x-x_1_{}_{}} \\ m=\frac{y-1}{x-0} \\ -1=\frac{y-1}{x} \\ -x=y-1 \\ y=-x+1 \end{gathered}[/tex]