inequalities

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inequalities

by smallsorrow » Mon Nov 17, 2008 10:29 am
If x-y > 10; is x-y >x+y ?

1) x=8
2) y=-20


it is pretty obvious that 2) is working - but why is 1)? maybe stupid q - but I just dont see it...
thanks for an answer...
Source: — Data Sufficiency |

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by stop@800 » Mon Nov 17, 2008 11:11 am
x-y>10


we need to find
x-y > x+y
or
-y > y
or
y<0

A
x=8

x-y>10
8-y>10
y< -2

this means y is negative
hence sufficient


B you have already cracked.

Hope thsi helps!!