Q22:

If x is negative, is x < -3?

(1) x² > 9

(2) x³ < -9

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

Answer: Thanks!

B

X^3<-9

X<-3条件2充分

谢谢!

不过偶的想法不同，偶选A。

由（1）推出 x<-3 或者 x>3，由于题目说 x是负数，所以 x < -3，（1）充分。

由 (2) 推出 x < - 3 ^2/3，由于 -3 ^2/3 > -3，所以不能推出 x < -3，所以（2）不充分。

Q22:

If x is negative, is x < -3?

(1) x² > 9

(2) x³ < -9

1) x^2 > 9, then |x| > 3 => x < -3 if x < 0, x > 3 if x > 0, since we already know x < 0, then x < -3, thus 1) by itself is sufficient

2) x^3 < -9, x < -(9)^(1/3), since 3 > 9^(1/3) => -3 < -9^(1/3), x < -9^(1/3) is not sufficient to establish that x < -3, thus 2) by itself is not sufficient

Therefore, the answer is A

呵呵，我刚起来的说

A对.

偶没有看到 x is negative这个条件.粗心了.

还有一种解法：

(2) x³ < -9