Q: If XY+Z=X(Y+Z), then which of the following must be true?
1. X=0,Z=0
2. X=1,Y=1
3. Y=1,Z=0
4. X=1, Y=0
5. X=1,Z=0
OA is 5.
Very simple problem but I got confused. Please help me guys!
Cheers!
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user123321
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xy+z = xy + xzAhmed MS wrote:Q: If XY+Z=X(Y+Z), then which of the following must be true?
1. X=0,Z=0
2. X=1,Y=1
3. Y=1,Z=0
4. X=1, Y=0
5. X=1,Z=0
OA is 5.
Very simple problem but I got confused. Please help me guys!
Cheers!
z = xz
z(x-1) = 0
x=1 or z=0
user123321
Just started my preparation 
Want to do it right the first time.
Want to do it right the first time.
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tpr-becky
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if xy + z = x(y + z) you have to apply the distributive rule to get xy + z = xy + xz.subtract out the xy to get z = xz.
The only way for z to equal xz is if z = 0 or x = 1
The answers are written confusingly here- it is clear that the comma is supposed to be an "or" but without that clarification the problem is difficult to answer.
The only way for z to equal xz is if z = 0 or x = 1
The answers are written confusingly here- it is clear that the comma is supposed to be an "or" but without that clarification the problem is difficult to answer.
Becky
Master GMAT Instructor
The Princeton Review
Irvine, CA
Master GMAT Instructor
The Princeton Review
Irvine, CA
