state Wheater the lines are parallel,perpendicular or neither

Question

 y=2x+5

y=-1/2x-4

Answer 1

Compare the slopes.  If they are equal, the lines are parallel.  If one slope is the negative reciprocal of the other, the lines are perpendicular.  If neither of these 2 conditions hold, then the lines are neither parallel or perpendicular.  Now look at the given slopes of 2 and -1/2.  Which of the three cases above do you see?

Answer 2

They are perpendicular because the slopes are negative reciprocals