Answer:
7) perpendicular
8) perpendicular
Explanation:
If the equations are in the form:
y = mx + b
(they all are in this form in these questions)
the m, the number in front of the x, is the slope.
If the slopes are the "negative reciprocals" (opposite signs and flipped over from each other) of each other, then the lines are perpendicular.
You can also do a quick check by, if the m values are multiplied together you should get -1.
1/3 • - 3 = -1
1 • -1 = -1
1/3 and -3 have opposite signs and are reciprocals (flipped over)
1 and -1 are opposite signs. It isn't very obvious maybe that they are reciprocals, but they are. Like 1/1 flipped over is 1/1.