Answer
undefined;
zero
Work Step by Step
RECALL:
(1) The graph of the equation $x=h$ where $h$ is a real number is a vertical line whose x-intercept is $(h, 0)$. The slope of a vertical line is undefined.
(2) The graph of the equation $y=k$ where $k$ is a real number is a horizontal line whose y-intercept is $(0, k)$. The slope of a horizontal line is zero.
Thus, the missing expressions in the given statement are (in order):
undefined;
zero
