Are the lines y=-x-4 and 5x+5y=20 perpendicular? Explain.

a)Yes; the product of their slopes is -1.
b)No; their slopes are equal.
c)Yes; their slopes are equal.
d)No; their slopes are not equal

Question

Are the lines y=-x-4 and 5x+5y=20  perpendicular? Explain.
 	
	a)Yes; the product of their slopes is -1.
	b)No; their slopes are equal.
	c)Yes; their slopes are equal.
	d)No; their slopes are not equal

lncognlto · Answer

Well, which do you think the answer is?

lncognlto · Answer

The slope of a line times the slope of the perpendicular is always equal to -1, and if the slope of two lines multiplied = -1, then they are perpendicular.

anonymous · Answer

d

lncognlto · Answer

Uh uh. What is the slope of each line?

anonymous · Answer

b because i know their not perpendicular

lncognlto · Answer

Yep, that's correct! :)

anonymous · Answer

so their slopes are equal??

lncognlto · Answer

Yes, both the slopes are equal to -1. -5/5 = -1.