Geometry - Need help

Question

Determine whether the pair of lines is parallel, perpendicular, or neither.

y = 2x + 1

2x + y = 7

Answer 1

Parallel if (a) slope is the same (b) lines are not identical

y = 2x + 1 has slope 2

2x + y = 7, rearranges to y = -2x + 7, slope = -2

slopes not the same, so not parallel

perpendicular if product of the slopes = -1. product of slopes = 2 x -2 = -4. so not perpendicular

Mike