If xy+z=x(y+z), which of the following must be true?
A.x=0,z=0,
B.x=1,z=1
C.y=1 and z=0
D.x=1 or y=0
E.x=1 or z=0
OA Is E...
GPREP (Properties of Numbers)
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Last edited by zagcollins on Mon Jul 28, 2008 6:13 am, edited 1 time in total.
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Do we need to solve the eauation and find the values of X, y, z or the question mean for what values of X, y , Z the equation will be always true..
I understood it as the later one.. hence i opted for Zero, bcoz if its ) the LHS = RHS.. and will always hold true...
I understood it as the later one.. hence i opted for Zero, bcoz if its ) the LHS = RHS.. and will always hold true...
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Well if you go by that way even the second option would hold true, x=1,z=1sudhir3127 wrote:Do we need to solve the eauation and find the values of X, y, z or the question mean for what values of X, y , Z the equation will be always true..
I understood it as the later one.. hence i opted for Zero, bcoz if its ) the LHS = RHS.. and will always hold true...
xy+z=x(y+z)
y+1=y+1
On GMAT you cannot have 2 right answers, therefore option E is the correct.
I hope its clear.