Answer
$\text{Slope: }
-1
\\\text{$y$-intercept: }
4$
Work Step by Step
The given equation is equivalent to
\begin{array}{l}\require{cancel}
y=4-x
\\\\
y=-x+4
.\end{array}
Using $y=mx+b$ (where $m$ is the slope and $b$ is the $y$-intercept) or the Slope-Intercept Form of linear equations, then the equation, $
y=-x+4
,$ has the following properties:
\begin{array}{l}\require{cancel}
\text{Slope: }
-1
\\\text{$y$-intercept: }
4
.\end{array}