DS Quesiton

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DS Quesiton

by GoMBA » Tue Sep 09, 2008 1:04 am
Can anyone tell me how to solve the attached DS question?
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by alescau » Sun Sep 14, 2008 3:34 pm
either one by itself is insufficient, b/c you can have the slope product be - while satisfying the condition.

make a table for each condition with 2 possible cases that satisfy the condition:

X:

L + -
K + -


Y:

L + -
K - +

when x and y signs are the same, we get a negative slope and a positive one when they are opposite. now match X with Y case by case and imagine what slopes these lines have to convince yourself.

both statements are sufficient together.

i don't think there's an easy way to this. you just have to be good at drawing lines in your head.