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Source: — Data Sufficiency |

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by kvcpk » Sun Aug 01, 2010 5:25 am
Is sqrt((x-3)^2) = 3-x

1)x != 3
put x = 1
LHS = 2 or -2
RHS = 2
So LHS may be or may not be equal to RHS
INSUFF

2) -x|x|>0
when x>0,
-x(x)>0
-x^2>0
x^2<0
this is not possible.
Hence x should be less than 0.

When x<0, x-3<-3 and 3-x>3

sqrt((x-3)^2) has two roots in which one is positive and the other is negative.
since x-3 should always be less than -3, it has only one root now.

this root will always not equal to 3-x. since 3-x is always >3

Hence SUFF

pick B