ds - |x|

Question

is |x| = y-z ?

1) x+y=z

2) x<0

(from gmatprep)

gotoknow3 · Answer

st1: not suff x=z-y |x| can be x or -x
st2; not suff
1+2 suff
C

FN · Answer

C as well... |x|=y-z? (1) theoratically |x| has two conditions... (x>0 and x<0) |x|=y-z (if x>0) if (x<0) then -(-x)=y-z => |x|=z-y so (1) is insuff (2) just tells us X <0... combined sufficient...

need700111 · Answer

i am getting A....

what is the OA please

christoph · Answer

OA is C !

|x| = x if x=+ve but |x| <> x if x=-ve

1) x+y=z or x=z-y is x +ve or -ve ? we dont know ? insuff

2) x<0 insuff

1)+2) x is -ve and the difference between y and z is x. the value of the two eq`s is the same but the sign is different. |x| <> -x !

KocharRohit · Answer

Hi , I tried doing like this ..dont know if it's a right approach..

|x|=y-z? 
we have to prove x = - (y-z) and x = y -z 
x = z - y and x = y - z

if these conditions are met we are done!!!
from condition 1st ) x = z - y..now how did we proof second???

taking x < 0...please throw some lights...

Rohit

ds - |x|

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards