GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 20 Oct 2019, 17:04

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# What is the value of x^(-4)? (1) x^(-2) = 225 (2) x^4 = 1/50,625

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 58434
What is the value of x^(-4)? (1) x^(-2) = 225 (2) x^4 = 1/50,625  [#permalink]

### Show Tags

28 Mar 2018, 23:33
00:00

Difficulty:

5% (low)

Question Stats:

97% (00:42) correct 3% (00:33) wrong based on 43 sessions

### HideShow timer Statistics

What is the value of $$x^{(-4)}$$?

(1) $$x^{(-2)} = 225$$

(2) $$x^4 = \frac{1}{50,625}$$

_________________
examPAL Representative
Joined: 07 Dec 2017
Posts: 1153
Re: What is the value of x^(-4)? (1) x^(-2) = 225 (2) x^4 = 1/50,625  [#permalink]

### Show Tags

29 Mar 2018, 00:34
Bunuel wrote:
What is the value of $$x^{(-4)}$$?

(1) $$x^{(-2)} = 225$$

(2) $$x^4 = \frac{1}{50,625}$$

As all we're given is equations, we'll look for a simplification-based approach.
This is a Precise methodology.

(1) Since $$(a^b)^c=a^{bc}$$ then we can raise our original expression to the power of 2 to get $$x^{(-4)}= (x^{(-2)})^2 = 225^2$$
Sufficient.

(2) Since $$a^{(-b)} = \frac{1}{a^b}$$ then we know that $$x^{(-4)} = 50,625$$
Sufficient.

_________________
Re: What is the value of x^(-4)? (1) x^(-2) = 225 (2) x^4 = 1/50,625   [#permalink] 29 Mar 2018, 00:34
Display posts from previous: Sort by