In order to answer this one, you have to remember:
--> Parallel lines have equal slopes.
--> Perpendicular lines have negative reciprocal slopes.
(One slope = - [ 1/the other slope ]
The question gives us two lines:
#1). y = 2x + 1
#2). 2x + y = 7
The first equation is in nice slope-intercept form, and we can see
right away that the slope of its graph is 2 .
The second equation is not in slope-intercept form, so we need to
massage it slightly before we can spot the slope of its graph.
2x + y = 7
Subtract 2x from each side: y = -2x + 7 . <== slope-intercept form.
Slope = -2 .
Now we know both slopes.
#1). Slope = 2
#2). Slope = -2
Are the slopes equal ? I don't think so. 2 is not equal to -2 .
The lines are not parallel.
Are the slopes negative reciprocals ? I don't think so.
2 is not equal to -[ 1/(-2) ].
The lines are not perpendicular.
