xy+z=xy+xz
xy cancels
z=xz
xz-z=0
z(x-1)=0
x=1, z=0
IMO E
gmat prep question
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logitech
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xy + z = x(y+z)steinbock wrote:If xy + z = x(y+z), which of the following must be true?
A) x=0 and z=0
B) x=1 and y=1
C) y=1 and z=0
D) x=1 and y=0
E) x=1 and z=0
OA is E
Can someone please provide an explanation? Thanks.
xy+z=xy+xz ( we can cancel both XZ from the sides )
z=xz
Z-xz=0
z(1-x)=0
z=0
OR
1-x=0
SO, x=1 and z= 0
LGTCH
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gmat009
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Can someone plz. help me understand this problem.steinbock wrote:If xy + z = x(y+z), which of the following must be true?
A) x=0 and z=0
B) x=1 and y=1
C) y=1 and z=0
D) x=1 and y=0
E) x=1 and z=0
OA is E
Can someone please provide an explanation? Thanks.
I am getting z(1-x)=0
Therefore , z=0 or x=1
Also xy=0 as it got cancelled from both sides.
So if x=1 then y=0 to get xy=0
So I am getting ans D instead of E
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logitech
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Two things:gmat009 wrote:Can someone plz. help me understand this problem.steinbock wrote:If xy + z = x(y+z), which of the following must be true?
A) x=0 and z=0
B) x=1 and y=1
C) y=1 and z=0
D) x=1 and y=0
E) x=1 and z=0
OA is E
Can someone please provide an explanation? Thanks.
I am getting z(1-x)=0
Therefore , z=0 or x=1
Also xy=0 as it got cancelled from both sides.
So if x=1 then y=0 to get xy=0
So I am getting ans D instead of E
1) XY did not cancelled becaused it was equal to ZERO, but it was at the both side of the equation
bla bla + XY = cha cha + XY
Bla bla = Cha CHa
2) You are solving the equation for Z and X so choose E
LGTCH
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"DON'T LET ANYONE STEAL YOUR DREAM!"
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jimmiejaz
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Hi Logitech,logitech wrote:Two things:gmat009 wrote:Can someone plz. help me understand this problem.steinbock wrote:If xy + z = x(y+z), which of the following must be true?
A) x=0 and z=0
B) x=1 and y=1
C) y=1 and z=0
D) x=1 and y=0
E) x=1 and z=0
OA is E
Can someone please provide an explanation? Thanks.
I am getting z(1-x)=0
Therefore , z=0 or x=1
Also xy=0 as it got cancelled from both sides.
So if x=1 then y=0 to get xy=0
So I am getting ans D instead of E
1) XY did not cancelled becaused it was equal to ZERO, but it was at the both side of the equation
bla bla + XY = cha cha + XY
Bla bla = Cha CHa
2) You are solving the equation for Z and X so choose E
Have sent a pm to you... Pls respond!!!!
Rajiv
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schakiiieee
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Shouldnt it much rather say "or" instead of "and" in answer choice E? (E is still the best answer choice)
The Qn says which of the following must be TRUE
and also the answer choice has
x=1 and z=0
The "and"
I think this should be OR
if z=0, any value is acceptable for x
so E is also not correct, as the Qn is must be true
and also the answer choice has
x=1 and z=0
The "and"
I think this should be OR
if z=0, any value is acceptable for x
so E is also not correct, as the Qn is must be true
