Hi there,
Could you explain in the simplest this concept and how to resolve it
What is the value of xy ?
(1) y = x + 1
(2) y = x (square) + 1
DS - XY value
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I'd go with C
1. y = x + 1
Xy = x(x+1)
Xy = x^2+x Insuff.
2. y = x^2+1
Xy = x(x^2+1)
Xy = X^3+x Insuff.
1+2
X+1 = x^2+1...............or x = x^2
0 = X^2 - x
0 = X(x-1)
Case 1: x = 0
Then XY must equal 0
Case 2: x-1=0.........................or x = -1
Plug this back into first equation y = x+1
Y = 0
Then XY must equal 0.
Sufficient.
1. y = x + 1
Xy = x(x+1)
Xy = x^2+x Insuff.
2. y = x^2+1
Xy = x(x^2+1)
Xy = X^3+x Insuff.
1+2
X+1 = x^2+1...............or x = x^2
0 = X^2 - x
0 = X(x-1)
Case 1: x = 0
Then XY must equal 0
Case 2: x-1=0.........................or x = -1
Plug this back into first equation y = x+1
Y = 0
Then XY must equal 0.
Sufficient.
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naval,
quick q on this part -
1+2
X+1 = x^2+1...............or x = x^2
at this point, i test x = 1 or x = 0 as both meet that rule.
so to determine xy, if x = 0, then xy = 0. if x = 1, then y is 2.
since we get 2 values for xy, i chose E. your method looks to be in line though so could you tell me where i missed this?
quick q on this part -
1+2
X+1 = x^2+1...............or x = x^2
at this point, i test x = 1 or x = 0 as both meet that rule.
so to determine xy, if x = 0, then xy = 0. if x = 1, then y is 2.
since we get 2 values for xy, i chose E. your method looks to be in line though so could you tell me where i missed this?
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- Master | Next Rank: 500 Posts
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Will be E. xy can either be 0 or 2.Xbond wrote:Hi there,
Could you explain in the simplest this concept and how to resolve it
What is the value of xy ?
(1) y = x + 1
(2) y = x (square) + 1
-
- Master | Next Rank: 500 Posts
- Posts: 208
- Joined: Sat Jan 31, 2009 11:32 am
- Location: Mumbai
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How do you get x=-1.It should be 1navalpike wrote:I'd go with C
1. y = x + 1
Xy = x(x+1)
Xy = x^2+x Insuff.
2. y = x^2+1
Xy = x(x^2+1)
Xy = X^3+x Insuff.
1+2
X+1 = x^2+1...............or x = x^2
0 = X^2 - x
0 = X(x-1)
Case 1: x = 0
Then XY must equal 0
Case 2: x-1=0.........................or x = -1
Plug this back into first equation y = x+1
Y = 0
Then XY must equal 0.
Sufficient.