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variables

by deagez » Fri Oct 30, 2009 6:49 pm
if xy+z = x(y+z) then which of the following must be true?

a) x=0 z=0
b) x=1 y=1
c) y=1 z=0
d) x=1 z=0
e) x=1 z=0

OA is E
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Re: variables

by life is a test » Sun Nov 01, 2009 6:50 am
deagez wrote:if xy+z = x(y+z) then which of the following must be true?

a) x=0 z=0
b) x=1 y=1
c) y=1 z=0
d) x=1 z=0
e) x=1 z=0

OA is E
xy+z = x(y+z) -> xy+z = xy+xz -> z=xz-> you can eliminate choices b and c since it doesnt matter what the y value is.

if z=xz then x must either be 1 or z =0.

hope that helps.
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