ANSWER :
y = -x - 1
EXPLANATION :
Using the two-point formula :
[tex]y-y_1=\frac{y_2-y_1}{x_2-x_1}(x-x_1)[/tex]From the problem, the two points are (0, -1) and (-6, -7)
[tex]\begin{gathered} y-(-1)=\frac{-7-(-1)}{-6-0}(x-0) \\ y+1=\frac{-6}{-6}(x) \\ y+1=-x \\ y=-x-1 \end{gathered}[/tex]