Answer:
3
3
-1/3
Parallel
Perpendicular
Perpendicular
Explanation:
You need to learn this for some tests where you don't get access to the internet in most cases like the ACT, SAT, normal tests, ect.
The formula for slope is y2-y1 divided by x2-x1
y2 is a point from the second pair of points, for example (-1, 4) or (2, 7).
y1 is a point from the first pair like (-5, -8), or (0, 1).
You can plug in the values for example:
4 - (-8) / -1 - (-5)
Two negatives equals a positive in math, so
12 / 4
= 3.
The slope for line 1 is 3.
You extend this to the other two lines.
For lines to be parallel, they must have the same slope.
1 and 2 should both have a slope of 3 based on the previous algebra, so they are parallel.
Line 3 has a slope of -1/3 which makes it perpendicular to 1 and 2, because perpendicular lines have the negative reciprocals of each other.
For example, if a line has a slope of 2, the perpendicular line has a slope of -1/2 because a reciprocal is the number flipped upside down with a fraction (aka, multiplying something with 1/x where x is the original number.)
A reciprocal slope of 19348 is -1/19348.