perpendicular lines have negative reciprocal slopes
since x=4 has a zero slope
the slope will be undefined or y= something
since it passes thru (3.5)
y=5
Choice A
points that are on x=5 must have the x coordinate = to 5
(5, something)
Choice B (5,0) (5,-2)
Parallel lines have the same slope x=7 has a slope of zero
so it must be a horizontal line x = something
it can't equal y because then the slope is 1
x must equal 4
Choice D
