The answer is: they are not parallel because they do not share the same slope.
Facts:
1. Two parallel lines share the same slope.
2. To determine a slope, express the equations in this form:
3. m = slope
The slope of is zero, because it represents a horizontal line in the cartesian plane.
We know that a slope = rise/run... in this case there is no rise and the run goes to infinity (+ and - directions). When zero is divided by any number, the result is zero... thus the slope is zero.