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

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Answer 1 · 2017-11-29T05:07:11

Perpendicular.

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.

Are these lines 8x - y = 7 and x + 8y = 78x - y = 7 and x + 8y = 7 parallel, perpendicular or neither?