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PS Problem - Explanation required

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by pratyoosh » Sun Nov 28, 2010 9:16 am
Hello,

Can someone opine on the solution to the below problem:

If xy + z = x(y + z), which of the following must be true?

1. x = 0 and z = 0
2. x = 1 and y = 1
3. y = 1 and z = 0
4. x = 1 or y = 0
5. x = 1 or z = 0

Ans : E

Thanks.
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Source: — Problem Solving |

by beat_gmat_09 » Sun Nov 28, 2010 9:30 am
xy + z = x(y+z)
xy + z = xy + xz
z=xz
z-xz=0
z(1-x)=0
z=0 or x=1
option E
Hope is the dream of a man awake
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by pratyoosh » Sun Nov 28, 2010 11:06 am
Thanks. I was trying to substitute the values as opposed to solving the set of equations, which is easier an option !
beat_gmat_09 wrote:xy + z = x(y+z)
xy + z = xy + xz
z=xz
z-xz=0
z(1-x)=0
z=0 or x=1
option E
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by rishab1988 » Sun Nov 28, 2010 11:10 am
Damn almost every question ,already,solved on the forum.I'm looking for unanswered questions...
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