Answer
$f(x)=3x-2$
Work Step by Step
Using $y=mx+b$ where $m$ is the slope, the given equation, $
3x-y=5
,$ is equivalent to
\begin{array}{l}\require{cancel}
-y=-3x+5
\\\\
y=3x-5
.\end{array}
Hence, the slope is $m=3$. Since parallel lines have the same slope, then $m_p=3$
Using $
(-1,-5)
$ and $m_p=
3
,$ the equation of the line is
\begin{array}{l}\require{cancel}
y-(-5)=3(x-(-1))
\\\\
y+5=3(x+1)
\\\\
y+5=3x+3
\\\\
y=3x+3-5
\\\\
y=3x-2
.\end{array}
In function notation form, this is equivalent to $
f(x)=3x-2
.$