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Complicated Expression
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Abdulla
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OA is 2
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Last edited by Abdulla on Sun Nov 22, 2009 10:21 pm, edited 1 time in total.
Abdulla
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heshamelaziry
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IMO D. (4x^2-9y^2)(4x^2+9y^2)/2x+3y = 3(4x^2+9y^2)
Cross multiply, we get:
3(4x^2+9y^2)/4x^2+9y^2 = (4x^2 - 9y^2)/ 2x + 3y
3= (2x-3y)(2x+3y)/2x + 3y
(1) 2x - 3y = 3
(2) 4x + 3y = 9
subtrtact 1 from 2 we get 2x = 6 --------> x = 3
Cross multiply, we get:
3(4x^2+9y^2)/4x^2+9y^2 = (4x^2 - 9y^2)/ 2x + 3y
3= (2x-3y)(2x+3y)/2x + 3y
(1) 2x - 3y = 3
(2) 4x + 3y = 9
subtrtact 1 from 2 we get 2x = 6 --------> x = 3
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thephoenix
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heshamelaziry wrote:IMO D. (4x^2-9y^2)(4x^2+9y^2)/2x+3y = 3(4x^2+9y^2)
Cross multiply, we get:
3(4x^2+9y^2)/4x^2+9y^2 = (4x^2 - 9y^2)/ 2x + 3y
3= (2x-3y)(2x+3y)/2x + 3y
(1) 2x - 3y = 3
(2) 4x + 3y = 9
subtrtact 1 from 2 we get 2x = 6 --------> x = 3
solving above two eqn we get x=2...pls check...
IMO x is 2
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thephoenix
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with OA is 3 do u mean its option three or value of x as 3Abdulla wrote:OA is 3
kindly check
as the value of x is coming as 2 which is option 3
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heshamelaziry
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thephoenix wrote:heshamelaziry wrote:IMO D. (4x^2-9y^2)(4x^2+9y^2)/2x+3y = 3(4x^2+9y^2)
Cross multiply, we get:
3(4x^2+9y^2)/4x^2+9y^2 = (4x^2 - 9y^2)/ 2x + 3y
3= (2x-3y)(2x+3y)/2x + 3y
(1) 2x - 3y = 3
(2) 4x + 3y = 9
subtrtact 1 from 2 we get 2x = 6 --------> x = 3
with 2x = 6, how can x = 2 ?
solving above two eqn we get x=2...pls check...
IMO x is 2
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Abdulla
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heshamelaziry wrote:thephoenix wrote:heshamelaziry wrote:IMO D. (4x^2-9y^2)(4x^2+9y^2)/2x+3y = 3(4x^2+9y^2)
Cross multiply, we get:
3(4x^2+9y^2)/4x^2+9y^2 = (4x^2 - 9y^2)/ 2x + 3y
3= (2x-3y)(2x+3y)/2x + 3y
(1) 2x-3y = 3
(2) 4x + 3y = 9
subtrtact 1 from 2 we get 2x = 6 --------> x = 3
with 2x = 6, how can x = 2 ?
solving above two eqn we get x=2...pls check...
IMO x is 2
My bad the answer is 2..
Final step is ..
2x-3y = 3
4x + 3y = 9 Add 2 equations
6x = 12
x = 2
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Last edited by Abdulla on Sun Nov 22, 2009 10:30 pm, edited 6 times in total.
Abdulla
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thephoenix
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subtracting 1 from 2 we get 2x+6y=6 [spoiler]not 2x=6[/spoiler]heshamelaziry wrote:thephoenix wrote:heshamelaziry wrote:IMO D. (4x^2-9y^2)(4x^2+9y^2)/2x+3y = 3(4x^2+9y^2)
Cross multiply, we get:
3(4x^2+9y^2)/4x^2+9y^2 = (4x^2 - 9y^2)/ 2x + 3y
3= (2x-3y)(2x+3y)/2x + 3y
(1) 2x - 3y = 3
(2) 4x + 3y = 9
subtrtact 1 from 2 we get 2x = 6 --------> x = 3
with 2x = 6, how can x = 2 ?
solving above two eqn we get x=2...pls check...
IMO x is 2
whereas adding eqn1 and eqn2 we are getting 6x=12--------->x=2
