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 April 27th, 2013, 09:09 PM #1 Member   Joined: Mar 2013 Posts: 36 Thanks: 0 Algebra simplification Hi! I am unsure of the intermediate steps in these equations: 1. When I multiply through by -1, the equations don't remain equal. What's the intermediate step? 2. My simplification gives: April 28th, 2013, 04:28 AM #2 Global Moderator   Joined: Oct 2008 From: London, Ontario, Canada - The Forest City Posts: 7,957 Thanks: 1146 Math Focus: Elementary mathematics and beyond Re: Algebra simplification 1. If you mean , multiply through by 3. 2. April 28th, 2013, 04:44 AM   #3
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Quote:
 Originally Posted by Aftermath When I multiply through by -1, the equations don't remain equal.
That doesn't make sense, as the equations (x - 3) = 18 and -(x - 3) = -18 are equivalent. Why would you want to multiply by -1 anyway? This problem started with an expression; should it have started with an equation? April 28th, 2013, 02:41 PM   #4
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Re: Algebra simplification

Thank you.

Quote:
 Originally Posted by greg1313 1. If you mean , multiply through by 3.

[/quote]2. [/quote]
I just realized that the two (2) is a shared denominator. April 28th, 2013, 02:45 PM   #5
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Quote:
Originally Posted by skipjack
Quote:
 Originally Posted by Aftermath When I multiply through by -1, the equations don't remain equal.
That doesn't make sense, as the equations (x - 3) = 18 and -(x - 3) = -18 are equivalent. Why would you want to multiply by -1 anyway? This problem started with an expression; should it have started with an equation?
It doesn't make sense indeed, tired post.

I multiply by -1 to remove the negative before the parentheses:

By the way, why is it that multiplying through by -1 doesn't change the sign inside the parentheses: April 28th, 2013, 03:10 PM #6 Global Moderator   Joined: Dec 2006 Posts: 20,916 Thanks: 2199 The exponentiation would need to be done first, and then the multiplication by -1 could be done by changing the sign of each term within the parentheses, not just the second term within the parentheses. -(x - 3)� = -(x� - 6x + 9) = -x� + 6x - 9 Tags algebra, simplification 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 arron1990 Algebra 3 August 14th, 2012 04:50 AM Jakarta Algebra 3 August 4th, 2012 10:45 AM euphmorning Algebra 10 July 17th, 2012 09:16 AM p3aul Algebra 5 January 23rd, 2011 09:11 PM wulfgarpro Algebra 13 May 16th, 2010 06:59 AM

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