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 June 17th, 2012, 12:20 AM #1 Newbie   Joined: Jun 2012 Posts: 6 Thanks: 0 Simplifying equation Hi friends, I have a following equation : x = x2 - [(N-1) * 2], where N = 11 that becomes: x = x2 - (20) My question: If possible, how can we derive the value of x in the equation x = x2 - (20) ? Thanks in advance, Regards. June 17th, 2012, 03:00 AM   #2
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Re: Simplifying equation

Quote:
 Originally Posted by bytelogik x = x2 - [(N-1) * 2], where N = 11 that becomes: x = x2 - (20) My question: If possible, how can we derive the value of x in the equation x = x2 - (20) ?
I assume x2 means x squared or x to the power 2: next time, show like this: x^2 (^ is power sign).

x = x^2 - 20
Rearrange:
x^2 - x - 20 = 0
Factor:
(x - 5)(x + 4) = 0

So x = 5 or x = -4

Any reason you were having trouble with that? Quite basic... June 17th, 2012, 03:15 AM #3 Newbie   Joined: Jun 2012 Posts: 6 Thanks: 0 Re: Simplifying equation Denis, thanks for your reply. But how do you figure out 5 and 4 ? What if the number 20 in the example equation is really a large value of which we do not know the products. Someone suggested for using quadratic formula for such equations. "Any reason you were having trouble with that? Quite basic..." Mathematics is a beautiful but complex arena and I am not even an average math expert. But I often try to solve really complex problems like 3D progression space for which I always want direct and simple equations. Studying progression sequences is just an part of it. I think learning and implementing maths to odd problems helps me to relax for a while and makes my logical strength more sharper. June 17th, 2012, 06:01 PM #4 Global Moderator   Joined: Dec 2006 Posts: 21,026 Thanks: 2257 x = x� - 20 is equivalent to (x - 1/2)� = 20 + 1/4, so you can find x - 1/2 and hence x. Tags equation, simplifying Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Similar Threads Thread Thread Starter Forum Replies Last Post Kinh Algebra 5 March 13th, 2014 11:00 PM windsurfer19 Algebra 3 December 2nd, 2013 12:15 PM jakeward123 Algebra 4 May 11th, 2012 12:37 PM cuteascanb Algebra 4 January 9th, 2011 05:45 AM cuteascanb New Users 1 December 31st, 1969 04:00 PM

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