well, the first line has a slope of -3, and runs through 0, -1.
a line parallel to that one, will have the same exact slope of -3.
now, we know about this other parallel line that it runs through -3,1, and of course, since is parallel, it has a slope of -3
[tex]\bf \begin{array}{ccccccccc}
&&x_1&&y_1\\
&&(~ -3 &,& 1~)
\end{array}
\\\\\\
% slope = m
slope = m\implies -3
\\\\\\
% point-slope intercept
\stackrel{\textit{point-slope form}}{y- y_1= m(x- x_1)}\implies y-1=-3[x-(-3)]
\\\\\\
y-1=-3(x+3)
\implies
y-1=-3x-9\implies y=-3x-8[/tex]
