It is currently 19 Oct 2017, 09:43

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

Author Message
Intern
Joined: 07 Oct 2011
Posts: 29

Kudos [?]: 6 [0], given: 1

### Show Tags

11 Oct 2011, 16:55
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 100% (00:03) wrong based on 1 sessions

### HideShow timer Statistics

if x<-1, is this inequality true?

x^3 + x ^4 > x^3 + x^2

let me know if this is right way to solve:

x^3 (1+x) > x^2(1+x)

canceling out 1+x since x not equal to 0

x^3 > x^2

canceling out x^2,
x>1

FALSE

but the OA is TRUE, what could be wrong?

Kudos [?]: 6 [0], given: 1

Manager
Joined: 20 Aug 2011
Posts: 144

Kudos [?]: 106 [1], given: 0

### Show Tags

11 Oct 2011, 17:36
1
KUDOS
There is a simpler way
You can subtract/add same number(s) on both sides of the inequality

x^3 + x ^4 > x^3 + x^2
Subtract x^3 from both sides
x^4>x^2
Divide both sides by x^2
x^2>1

True as x<-1
-------------------------

You can't cancel (1+x) right away because (1+x) is negative.

Consider this-
-18<-12
-6*3<-6*2
From what you say canceling -6 on both sides gives
3<2
Incorrect.

Makes sense?
_________________

Hit kudos if my post helps you.
You may send me a PM if you have any doubts about my solution or GMAT problems in general.

Last edited by blink005 on 11 Oct 2011, 17:42, edited 1 time in total.

Kudos [?]: 106 [1], given: 0

Intern
Joined: 07 Oct 2011
Posts: 29

Kudos [?]: 6 [0], given: 1

### Show Tags

11 Oct 2011, 17:39
yeah..clear now.. thanks a lot

Kudos [?]: 6 [0], given: 1

Display posts from previous: Sort by