Adding y on both sides of the in-equality

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by rakeshd347 » Tue Oct 01, 2013 11:50 pm
theCodeToGMAT wrote:
rakeshd347 wrote:
theCodeToGMAT wrote:It's the decision of Sri & YOU how you want to take my advise. I have fallen in a pitfall and have learnt my mistake.. The solution i have provided is 100% CORRECT.

Sri, one advise I will definitely give you... Be very careful while determinately adding variables in an inequality.

Good Luck!
Now let me give you a advice and again its up to you to take it or not.

first of all here is the mistake you made in the question which you sent me I have given the explanation.
https://www.beatthegmat.com/if-w-x-0-is- ... tml#695492

I don't know which gmat teacher has advised you not to add the same variable on both sides of the equation but you can do so safely.
Let me know if the mistake that I have pointed out to you make sense or not. But its utter fact that you can add or subtract the same variable from both sides even the way you have done it in the question which you sent me.
Rakesh, on same variable; i do agree.. but on playing in different variables.. i don't .. this is what i am insisting from starting.. when in inequalities.. try to solve using simple algebric approach.. similar to the method you say.. BUT, avoid adding variables.. here i meant.. different variables..
Well in your question you added different variable and that approach was not wrong even though not the best either. But it is fine. Look if you get confused with the inequality the best thing is to pick numbers. But I have showed you that what sri has asked is absolutely fine and I have also showed you that what you had done in your question x-x=0 is also fine. it may not be the best way to solve but its not wrong. I have solved number of problems doing this. If you do the Gmatclub test question half of the problems will blow you off and you have to come up with something like this.

Conclusion:

It is absolutely correct and now Rahul agrees to add new variable on both sides. It is also absolutely correct o do x-x=0. here you are not bringing new variable it is already in the question.

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by theCodeToGMAT » Tue Oct 01, 2013 11:54 pm
Yep, i agree on the same variable.. I misunderstood the contextual approach applied by Sri.. I took the question in form of adding a random variable which is missing in the Statement.. Sorry for confusion!
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