Answer
$y=-3x-2$
Work Step by Step
Using $y-y_1=m(x-x_1)$ or the Point-Slope Form of Linear Equations, then the equation of the line with slope $-3$ and containing the point $(1,-5)$ is
\begin{array}{l}\require{cancel}
y-(-5)=-3(x-1)
\\\\
y+5=-3x+3
\\\\
y=-3x+3-5
\\\\
y=-3x-2
.\end{array}
