If x, y, and z are nonzero numbers, is (x)(y + z) > 0?
(1) |x + y| = |x| + |y|
(2) |z + y| = |y| + |z|
(1) |x + y| = |x| + |y|
(2) |z + y| = |y| + |z|
St1) Tells us that X and Y have same signsbeater wrote:If x, y, and z are nonzero numbers, is (x)(y + z) > 0?
(1) |x + y| = |x| + |y|
(2) |z + y| = |y| + |z|
X,Y > 0 or X,Y<0 because if they have different signs |x + y| = |x| + |y| won't be correct.
(x)(y + z) > 0? we dont know anything about Z - INSUF
ST2) Z and Y same signs, no info for X INSUF
ST1+2)
now we know X,Y and Z have same signs!
Either they are both NEGATIVE or POSITIVE
(x)(y + z) will be greater than 0
-4 (-5+(-2) ) = 28
4 (5+2) = 28
So choose C
