Are these lines #8x - y = 7 and x + 8y = 7# parallel, perpendicular or neither?

1 Answer
Nov 29, 2017

Perpendicular.

Explanation:

Parallel lines have the same slope.

Perpendicular lines have slopes that are negative reciprocals of each other.

If you manipulate the second equation, you get:

#8y=-x+7#

By dividing. By #8# you get:

#y=-\frac{1}{8]x+7#

The slope here is the negative receiprocal of #8#, which is the slope of the other line.

#\therefore# the lines are perpendicular.