Answer
slope $=0$
y-intercept $=-1$
Refer to the image below for the graph.
Work Step by Step
RECALL:
(1) The slope-intercept form of a line's equation is:
$y=mx+b$
where $m$ = slope and $b$ = y-intercept
(2) A horizontal line has a slope of zero.
The equation of the line is in the form $y=k$ where $k$ is the y-intercept.
Every point on this line has a y-coordinate of $y=k$.
Thus, the given equation $y=-1$ is a horizontal line with a slope of $0$ and a y-intercept of $-1$
To graph the line, perform the following steps:
(1) Plot the y-intercept point $(0, -1)$.
(2) Plot another point with a y-coordinate of $-1$.
(3) Complete the graph by connecting the two points using a straight line.
(refer to the attached image in the answer part above for the graph)
