write the expression as (something)^2 = number, next somtheing is + or - sqrt(number)
2n^2= -1+6n
2n^2 - 6n + 1 = 0
[ sqrt(2) * N - sqrt(2)*6/4 ] ^2 -18 + 1 = 0;
thus
[ sqrt(2) * N - sqrt(2)*6/4 ] ^2 = 17
sqrt(2) * N - sqrt(2)*6/4 = + sqrt(17) or - sqrt(17)
etc ..
2007-11-03 06:22:59
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answer #1
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answered by gjmb1960 7
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2n^2= -1+6n
=> 2n^2 - 6n + 1 = 0
=> n^2 - 3n + 1/2 = 0
=> (n - 3/2)^2 - 9/4 + 2/4 =0
=> (n - 3/2)^2 = (√7/2)^2
=> n - 3/2 = ± √7/2
=> n = (1/2) * ( 3 ± √7)
2007-11-03 06:26:01
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answer #2
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answered by Madhukar 7
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2n^2 = - 1 + 6n
2n^2 - 6n + 1= 0
divide by 2 to make x^2 coefficient 1
n^2 - 3n + 1/2 = 0
(n)^2 - 2(3/2) n + 1/2 = 0
so to make it perfect square (3/2)^2 = 9/4 is missing
add 9/4 both sides
n^2 - 3n + 9/4 + 1/2 = 9/4
(n-3/2)^2 = 9/4 - 1/2
(n - 3/2)^2 = 7/4
n - 3/2 = +/- sqrt(7/4)
n = 3/2 +/ - sqrt(7)/2
n = [3 + sqrt(7)]/2 or [3 - sqrt(7)]/2
2007-11-03 06:36:48
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answer #3
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answered by mohanrao d 7
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2n^2-6n=-1
n^2-3n=-1/2
complete the square by adding 9/4 to each side we get
n^2-3n+9/4=9/4-1/2=7/4
(n-3/2)^2=7/4
n-3/2= +-sqrt7/2
n= +-sqrt7/2+3/2
2007-11-03 06:38:46
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answer #4
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answered by Kenneth H 3
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2n^2-6n+1=0
n^2-3n+(1\2)=0
use (b^2-4ac) and then use the equation [(-b+/-b^2-4ac)/2a]
it comes out n=2.207 or n=0.7928
2007-11-03 06:24:22
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answer #5
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answered by Anonymous
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2n^2-6n+1=0
ax^2+bx+c=0
a=2 b=-6 c=1
x=[-b+ or - sqrt(b^2-4ac)]/2a
evaluate two x's using +sqrt(b^2-4ac) and -sqrt(b^2-4ac)
You'll get fractional answers.
x=2.82 x=0.177
2007-11-03 06:36:00
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answer #6
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answered by cidyah 7
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2n^2 -6n = -1
2 (n^2 -3n) = -1
2 ((n - 1.5)^2 -2.25) = -1
(n -1.5)^2 - 2.25 = -0.5
(n - 1.5)^2 = 1.75
n - 1.5 = ±sqrt(7/4)
n = 1.5 ± (sqrt(7)/2)
n = 2.8228... or n = 0.17712...
2007-11-03 06:41:24
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answer #7
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answered by tinned_tuna 3
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2n^2-6n+1=0
n^2-3n+1/2=0
n^2-3n+(3/2)^2-(3/2)^2+1/2=0
(n-3/2)^2=(3/2)^2-1/2
(n-3/2)^2=9/4-1/2
(n-3/2)^2=7/4
n-3/2=sqrt(7)/2 or -sqrt(7)/2
so
n=3/2+sqrt(7)/2 or 3/2-sqrt(7)/2
2007-11-03 06:30:46
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answer #8
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answered by zsm28 5
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