Studying for GRE: Linear Inequalities  TOPIC_SOLVED

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Studying for GRE: Linear Inequalities

Postby mecmath327 on Sat Feb 28, 2009 11:22 pm

I am reviewing Algebra for my GRE test. Here is one inequality problem that I do not understand...
I will provide the equation, the choices of answers, and their answer. I want to know HOW they solved it! Thank you!

Equation:

the letter x represents variable "x"
Equation writing in words: If 3x PLUS 4 is GREATER THAN Seventeen, 3x PLUS 7 is GREATER THAN

If 3x + 4 > 17, 3x + 7 >

Choices for Answers:

A.

13
-----
3

B.

22
-------
3

C. 14


D. 17

E. 20


Their answer:

3x + 7 = (3x + 4) + 3 > 17 + 3 = 20


I appreciate any feedback for this type of inequality problem!
Thank You
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  TOPIC_SOLVED

Postby stapel_eliz on Sun Mar 01, 2009 12:31 am

mecmath327 wrote:Equation writing in words: If 3x PLUS 4 is GREATER THAN Seventeen, 3x PLUS 7 is GREATER THAN

If 3x + 4 > 17, 3x + 7 >

Just add "3" to either side:

3x + 4 >  17
+ 3 + 3
------------
3x + 7 > 20


Hope that helps! :D
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stapel_eliz
 
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Re: Studying for GRE: Linear Inequalities

Postby mecmath327 on Sun Mar 01, 2009 3:54 pm

stapel_eliz,
THANK YOU!!
I reviewed what you posted, and looked back at the problem...NOW it makes sense!!
I see now, they (in the original equation) gave a partial answer.
It was a matter of knowing what step to do on the left side, thus you have to do the step on the right side!!
Thanks again!
mecmath327
 
Posts: 2
Joined: Sat Feb 28, 2009 10:54 pm


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