slopes

[bmwhype]

If B E and A are not zeros, do lines y=(-A/B)x + C/B and y=(-D/E) + F/E cross?

1. A/B = D/E
2. E/B = D/A

[zuckerman]

Can you look at the second equation and correct it if required, or confirm that it is correct the way you have shown, please?

Thanks.

[siliconfish]

Ans D;

1. A/B = D/E; Slope are equal so lines are parallel;
2. E/B = D/A; => A/B = D/E; => Slope are equal so lines are parallel;

[smittty]

Can you please explain how statement 2 is correct.

[Ratandeep Singh]

E/B=D/A => A/B=D/E by cross-multiplication. Hence, this statement is same as 1. Hence, D is the answer.

[angryMOFO]

Good question.

[chasedream]

Answer should be E

1, A/B = D/E, D can be zero or not zero, but A is a non zero, so A/B is not zero. It means that, the two lines cross

2, is a vary of 1. So D is my choice

[Leonard C]

What if the two lines are exactly the same? Does that meet the definition of "cross"? Because if so, then shouldn't the answer be E eg. lines are different but parallel (do not cross), or lines are exactly the same (they cross).

[pareshpandit]

Originally Posted by Leonard C

What if the two lines are exactly the same? Does that meet the definition of "cross"? Because if so, then shouldn't the answer be E eg. lines are different but parallel (do not cross), or lines are exactly the same (they cross).

if the two lines are in fact the same line, then they do not cross...

for one thing, technically speaking, "cross" necessarily implies that the two lines meet at one and only one distinct point, that they have no other point in common...

secondly, even if you call the same line by two names, it still remains that very single line in actuality; now, a line cannot cross 'itself', can it?...

[Leonard C]

Great thanks, I saw a question on another test which asks whether two lines "touch". I said no as I didn't think a line could touch itself but apparently the OA did.

Thanks for clarifying any way. Some GMAT questions are pretty badly written in my opinion.