Answer: y = -7 and the slope is zero.
Step-by-step explanation:
A line parallel to the y-axis would have the same slope, and the slope of the y-axis is zero.
If the slope is zero and the line passes through the point (-10,-7), the y-intercept for the line is -7.
y = mx + b
y = 0x - 7
(zero x is just zero, so:)
y = -7