Answer
The slope is not defined because the line is vertical.
There is no $y$-intercept since the line does not pass through the $y$-axis..
Refer to the graph below.
Work Step by Step
The slope of the line can be obtained by looking at the coefficient of $x$ in the slope-intercept form.
$x=-4$ is a vertical line so its slope is not defined.
There is no $y$-intercept because this vertical line does not pass through the $y$-axis.