For 1-10, determine whether the lines are parallel, perpendicular or neither.

One line passes through the points (-1, 4) and (2, 6); another line passes through the points (2, -3) and (8, 1).
One line passes through the points (4, -3) and (-8, 0); another line passes through the points (-1, -1) and (-2, 6).
One line passes through the points (-3, 14) and (1, -2); another line passes through the points (0, -3) and (-2, 5).
One line passes through the points (3, 3) and (-6, -3); another line passes through the points (2, -8) and (-6, 4).
Both lines pass through the point (2, 8); one line also passes through (3, 5), and the other line has slope 3.

2 answers

I see 4 questions of the same type, with just different numbers.
The last one uses the same concepts, just stated in a different way.

I will do the 1st:
slope between the points (-1, 4) and (2, 6) = (6-4)/(2-(-1)) = 2/3
slope between the points (2, -3) and (8, 1) = (1-(-3))/(8-2) = 4/6 = 2/3

Since the slopes are the same, the lines are parallel

(If the lines are perpendicular, their slopes would be opposite reciprocals
e.g. 6/7 vs -7/6 , or -4/3 vs 3/4 )
i dont get it