Data Sufficiency (DS) | Re: Does b = 2b - a ?

Equating two even roots means the absolute value of variables under the radical must be same.

Whereas, Equating two odd roots means variables under the radical have same absolute value and same sign +-.

So, Q stem is asking us if a=b in value and sign or a=b=0.

St.1: a=-b.
Means two options for a&b:
*same value & opposite sign
*a=b=0
So, Insufficient.

St.2: a=2b
Means two options for a&b:
*differnt value & same sign
*a=b=0
So, Insufficient.

St.1+2: Combining two statements,
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