GMAT Data Sufficiency (DS) | Is |a-b|-(a-b)>0? 1) a0 and b>0

1. a<b
a could be positive/negative.
If a is positive, b is a bigger positive number
If a is negative, b could be positive. Also b could be a bigger negative number.
Whatever the case a-b will become negative.
The absolute value(which becomes positive) when subtracted by a negative number will always be positive.
This statement alone is sufficient.

2) a>0 and b>0
When both a and b are postive, we cannot say for sure which of the number is bigger.
If a>b, then the statement will
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