Pre Calculus Question

Determine whether likes L1 and L2 passing through the pairs of points are parallel, perpendicular, or neither.
L1: (1,4), (-8,-4)
L2: (-4,-6), (5,2)

Please answer it and explain how to do it, i'm having alot of troubles in Pre-calc..

To find whether lines are parallel, perpendicular, or neither, it all rests in the slopes.
--Parallel lines will have the same slope.
--With perpendicular lines, the slope of line A perpendicular to line B will be the negative reciprocal of the slope of line B.
If the slopes don't fit into either of these categories, the lines are neither parallel nor perpendicular.

Slope is (y2 - y1) / (x2-x1); basically, you're finding the difference in the y values over the difference in the x values. Find the slopes for both lines. See how they compare.

slope L1 = (-4 - 4) / (-8 -1) = -8 / -9 = 8 / 9
slope L2 = (2- (-6)) / (5- (-4)) = 8 / 9

The slopes are the same; L1 and L2 are parallel to each other

L1: you take difference between x values and y values. Thus -8 - 1 = -9 and -4 - 4 = -8
L2: you take difference between x values and y values. Thus 5 -(-4) = 9 and 2 -(-6) = 8

Slope is defined as rise/run or y/x

L1: -8/-9 = 8/9
L1: +8/+9 = 8/9

same slope means they are parallel

If you use the points to find the equation of the line, you get:
y=8/9x for the first line
and y=8/9x for the second
Thus they are parallel, because the slopes are equal