Are x and y both positive?
1) 2x-2y = 1
2) x/y > 1
X and Y
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hi guysnicajvch wrote:Are x and y both positive?
1) 2x-2y = 1
2) x/y > 1
don`t you think that the answer should be C
my thinking
(1) 2x-2y=1 insufficient but some operations
2x=1+2y
x=1/2+y
(2) x/y>1 insufficient as both x,y can be +ve or -ve
but both
x/y-1>0
(x-y)/y>0
and fron st1 x=1/2+y
(1/2+y-y)/y>0, here we cancel y and left with
(1/2)/y>0
as 1/2>0 without proving so y>0 for whole fraction to be >0
and x=1/2+y, where y>0 so x must be >0 so
C