You've Unlocked a New GMAT® Question!

Text Solution:

Question Stem Analysis:

We must determine the value of x + y.

Statement One Alone:

$\Rightarrow$ $\left|\mathrm{x}\right|+\left|\mathrm{y}\right|=9$

Let's test some numbers for x and y. We could let x = 5 and y = 4 since $\left|5\right|+\left|4\right|=9$. In this case x + y = 9. We could also let x = –5 and y = –4 since $\left|-5\right|+\left|-4\right|=9$. In this case x + y = –9. Because we get different values for x and y, statement one alone is not sufficient.

Eliminate answer choices: A and D

Statement Two Alone:

$\Rightarrow$ $\left|\mathrm{x}\right|-\left|\mathrm{y}\right|=3$

We can let x = 6 and y = 3 since $\left|6\right|-\left|3\right|=3$. In this case, x + y = 9. We could also let x = –6 and y = –3 since $\left|-6\right|-\left|-3\right|=3$. In this case, x + y = –9. Because of this contradiction, statement two alone is not sufficient.

Eliminate Answer Choice: B

Statements One and Two Together:

We can let x = 6 and y = 3 since $\left|6\right|-\left|3\right|=3$ and $\left|6\right|+\left|3\right|=9$. In this case, x + y = 9. We could also let x = –6 and y = –3 since $\left|-6\right|-\left|-3\right|=3$ and $\left|-6\right|+\left|-3\right|=9$. In this case, x + y = –9. Because of this contradiction, both statements together are not sufficient.

LEARNING JOURNAL

What went wrong, and what can you do differently next time?

Was there a particular sticking point, breakdown in your logic or conceptual knowledge, bad habit, or careless mistake that led you to the wrong answer? At what point in your process did that error occur?

Record an audio message

0:00

0

/

1500