rxs0005 wrote:
If xy > 0, does xy – y = 3?
(1) xy = 3
(2) y – 1 = 0
From the given statement xy>0, we can deduce that either x,y>0 or x,y< 0
St1 we have xy=3
possible values of x and y are
x=-1, y=-3, substituting in the given we get 3-(-3)=6 which is not equal to 3
x=3,y=1, we get 3-1= 2 not equal 3
x=9,y=1/3 3- 1/3= 8/3 not equal to 3
we can safely that say that for any values satisfying given st1 we do not have the expression value equal 3
Hence Option B,C,E ruled out
St 2, y-1=0-----> y=1
we know only the value of y and that x>0 which is not sufficient. In order to satisfy the given equation that is xy-y=3 value of x should be 4 which we are not sure of.
Hence Ans should be A
thanks
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