Guest Posted December 12, 2010 Report Share Posted December 12, 2010 Prove me wrong... -20=-20... 16-36=25-45... 4^2-9*4=5^2-9*5... 4^2-9*4+81/4=5^2-9*5+81/4... (ok this next parts tricky but it works out)... (4-9/2)^2=(5-9/2)^2... 4-9/2=5-9/2... 4=5... Quote Link to comment Share on other sites More sharing options...
0 bushindo Posted December 12, 2010 Report Share Posted December 12, 2010 (edited) On 12/12/2010 at 4:37 PM, wireman said: Prove me wrong... -20=-20... 16-36=25-45... 4^2-9*4=5^2-9*5... 4^2-9*4+81/4=5^2-9*5+81/4... (ok this next parts tricky but it works out)... (4-9/2)^2=(5-9/2)^2... 4-9/2=5-9/2... 4=5... That would be here Reveal hidden contents (4-9/2)^2=(5-9/2)^2 This is simply ( -1/2 )^2 = (1/2)^2 Which is true, but removing the square sign is now not allowed. Edited December 12, 2010 by bushindo Quote Link to comment Share on other sites More sharing options...
0 Guest Posted December 12, 2010 Report Share Posted December 12, 2010 On 12/12/2010 at 4:37 PM, wireman said: Prove me wrong... Reveal hidden contents (4-9/2)^2=(5-9/2)^2... 4-9/2=5-9/2...... But I feel this is not true. If X^2 = Y^2 then X = +/- Y Also whicle resolving the above problem, you need to put (4-9/2)^2=(5-9/2)^2 The solution should be ... Since 4 is not equal to 5, hence, 4-9/2 = - (5-9/2) 4-9/2 = -5 + 9/2 4+9 = 9/2 +9/2 9 = 9 Which is true in all ways. 4=5... Quote Link to comment Share on other sites More sharing options...
0 Guest Posted December 12, 2010 Report Share Posted December 12, 2010 Reveal hidden contents (4-9/2)^2=(5-9/2)^2 but as 4 - 9/2 < 0 taking the square root of both sides should actually give 9/2 - 4 = 5 - 9/2 Quote Link to comment Share on other sites More sharing options...
0 Guest Posted December 15, 2010 Report Share Posted December 15, 2010 Reveal hidden contents (4-9/2)^2=(5-9/2)^2 works only because the of the square which turns both sides into 1/4 when solved regardless of the -1/2 you start with on the left side of the equation. Simplifying the equation by applying the square root to both sides to remove the exponent leaves you with: 4-9/2=5-9/2 which isn't true. You actually end up with -1/2=1/2. When broken down this far it only works if you use the absolute value of the left side of the equation. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted December 17, 2010 Report Share Posted December 17, 2010 Reveal hidden contents (4-9/2)^2=(5-9/2)^2 removing square will always give 2 roots: + (4-9/2) = +(5-9/2) - - Choosing right one will right equation. -2^2 = 2^2 doesn't mean -4 = 4 Quote Link to comment Share on other sites More sharing options...
0 dark_magician_92 Posted January 2, 2011 Report Share Posted January 2, 2011 On 12/12/2010 at 4:37 PM, wireman said: Prove me wrong... -20=-20... 16-36=25-45... 4^2-9*4=5^2-9*5... 4^2-9*4+81/4=5^2-9*5+81/4... (ok this next parts tricky but it works out)... (4-9/2)^2=(5-9/2)^2... 4-9/2=5-9/2... 4=5... Reveal hidden contents hehe everything is right except the last step shud have been (4-9/2)=+(5-9/2) or 4-9/2=-(5-9/2) Quote Link to comment Share on other sites More sharing options...
0 Guest Posted January 2, 2011 Report Share Posted January 2, 2011 a^2 = b ^ 2 => √a^2 = √v^2 => a = +- b in your case you use only the + case, which is proved to be wrong! Quote Link to comment Share on other sites More sharing options...
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Guest
Prove me wrong...
-20=-20...
16-36=25-45...
4^2-9*4=5^2-9*5...
4^2-9*4+81/4=5^2-9*5+81/4...
(ok this next parts tricky but it works out)...
(4-9/2)^2=(5-9/2)^2...
4-9/2=5-9/2...
4=5...
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