Data Sufficiency

What is the value of x?
(1) – (x + y) = x - y
(2) x + y = 2

I think the answer is C.

(1) – (x + y) = x - y

All this tells us that X is negative. INSUFFICIENT

(2) x + y = 2

X and y could be a number of intergers to make this statement true. INSUFFICIENT

1 and 2 combined is


- (x+y) = x-y
we know from statement 2 that x+y = 2 so we subsittute

- (2) = x-y

so now -2 = x-y now we have 2 equations

x+y = 2
x-y = -2

the y's cancel out.

x = 0

both together are sufficient.


am i right?

Whats th OA ?

I think the answer is A.

1)

-(x+y)-x+y = 0
-2x = 0
=> x = 0. SUFFICIENT

2)

x+y = 2. INSUFFICIENT

So my choice is A.

Am i right ? Whats the OA ?

Please post the OA ....

IMO A.

A alone is sufficient to prove x=0.
-(x+y) = x-y

=> -x=x
=> x = 0

I guess i thought that since they asked what the value is that they wanted a specific number . if they dont want that, then yes, i guess -x=x would suffice.

Mclaughlin wrote:I guess i thought that since they asked what the value is that they wanted a specific number . if they dont want that, then yes, i guess -x=x would suffice.

They do want a specific number. Let's take -x = x one step further:

-x = x

add x to both sides to get:

-x + x = x + x

0 = 2x

0 = x

So, we know that the value of x is 0.