Data Sufficiency

Abhijit K wrote:What is the value of |x+7|?
1.|x+3|=14
2.(x+2)^2=169

Brent@GMATPrepNow wrote:

Uva@90 wrote:

Abhijit K wrote:What is the value of |x+7|?
1.|x+3|=14
2.(x+2)^2=169

Hi Abhijit,

We need value of X to find the value of |x+7|

Stmt1: |x+3|= 14
x+3 = 14 ==> x = 11
or x+3 = -14 ==> x = -17
since we have two values Insufficient.

Stmt 2: (x+2)^2=169

x+2 = 13 ==> x = 11
or x+2 = -13 ==> x = -15
since we have two values Insufficient.

1+2

we have common value of 11. Hence sufficient.
OA is C

Regards,
Uva

Hi Uva@90,

Be careful. Always keep remember that we're trying to answer the target question.
For each statement, we may have 2 possible values for x, BUT that doesn't necessarily mean that there are two different answers to the target question (What is the value of |x+7|?)

Consider, for example, if statement 2 looked like this:

Statement 2: (x+7)² = 100
There are two possible solutions to this equation: x = 3 and x = -17
Does this mean that statement 2 is not sufficient?
No. The target question is NOT asking us to find the value of x. It's asking us to find the value of |x+7|
If x = 3, then |x + 7| = |3 + 7| = |10| = 10
If x = -17, then |x + 7| = |-17 + 7| = |-10| = 10
So, although there are 2 possible values of x, there's ONLY ONE answer to the target question.
So, in this case, statement 2 is SUFFICIENT

Cheers,
Brent

Brent@GMATPrepNow wrote:

Uva@90 wrote:

Abhijit K wrote:What is the value of |x+7|?
1.|x+3|=14
2.(x+2)^2=169

Hi Abhijit,

We need value of X to find the value of |x+7|

Stmt1: |x+3|= 14
x+3 = 14 ==> x = 11
or x+3 = -14 ==> x = -17
since we have two values Insufficient.

Stmt 2: (x+2)^2=169

x+2 = 13 ==> x = 11
or x+2 = -13 ==> x = -15
since we have two values Insufficient.

1+2

we have common value of 11. Hence sufficient.
OA is C

Regards,
Uva

Hi Uva@90,

Be careful. Always keep remember that we're trying to answer the target question.
For each statement, we may have 2 possible values for x, BUT that doesn't necessarily mean that there are two different answers to the target question (What is the value of |x+7|?)

Consider, for example, if statement 2 looked like this:

Statement 2: (x+7)² = 100
There are two possible solutions to this equation: x = 3 and x = -17
Does this mean that statement 2 is not sufficient?
No. The target question is NOT asking us to find the value of x. It's asking us to find the value of |x+7|
If x = 3, then |x + 7| = |3 + 7| = |10| = 10
If x = -17, then |x + 7| = |-17 + 7| = |-10| = 10
So, although there are 2 possible values of x, there's ONLY ONE answer to the target question.
So, in this case, statement 2 is SUFFICIENT

Cheers,
Brent