Is the line for the equation y = −8 horizontal or vertical? what is the slope of this line?

Check the picture below.

so, say let's use two points on that line to see what's its slope then.

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

answer: 193

explanation:

200-7 = 193