2y^2-3y-1=0
(2y+1)(y-1)=0
2y+1=0
y-1=0
solve for y
2007-03-29 06:03:57
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answer #1
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answered by AKAdemiks 3
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2y^2-3y=1
First subtract 1 from both sides
2y^2-3y -1
This can be then factorised by using the quadratic equation
y = (3 + or - sqrt(3^2 + 4*2*1))/ (2*2)
y = ( 3 + or - sqrt(9 + 8))/ 4
y = (3 + or - sqrt(17))/ 4
y1= (3 + sqrt(17))/ 4 = 1.7808
y2 = (3 - sqrt(17))/ 4 = -0.2808.
2007-03-29 13:06:21
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answer #2
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answered by The exclamation mark 6
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divide the whole thing by 2
y^2 - 1.5y = 0.5
Add the square of half of 1.5 to both sides
y^2 - (3/2)y + 9/16 = 8/16 + 9/16 = 17/16
which gives (y - 3/4)^2 = 17/16
y - 3/4 = +/-sqrt(17/16)
y = 3/4 +-sqrt(17/16)
2007-03-29 13:08:47
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answer #3
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answered by biglildan 6
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Hi,
Move everything to one side.
2y^2 -3y-1=0
This does not factor, so plug it into the quadratic formula. The Quadratic Formula uses the "a", "b", and "c" from "ax^2 + bx + c", where "a", "b", and "c" are just numbers. For you, a = 2, b = -3, and c = -1.
[ -b + or - sqrt(b^2 -4ac)]/(2a) is the quadratic formula. For this problem, it becomes:
y = [ -b + or - sqrt(b^2 -4ac)]/(2a)
y = [ -(-3) + or - sqrt((-3)^2 -4(2)(-1))]/(2(2))
OR
-(-3) + or - sqrt((-3)^2 -4(2)(-1))]
-----------------------------------------------
________ (2(2))
which simplifies to
3 + or - sqrt(9 +8)
------------------------- = y
4
3 + or - sqrt(17)
---------------------- = y
4
This is your answer unless you want decimals for it. They are about 1.78 or -.28
I hope that helps!
2007-03-29 13:46:08
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answer #4
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answered by Pi R Squared 7
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Sure! Subtract the 1.
You get 2y^2-3y-1=0
Use the quadratic formula: -b +/- b^2 - 4ac
all over 2a. (It looks better on paper.)
Simplify, and you get 3 +/- 17 all over 4.
Good luck.
2007-03-29 13:03:41
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answer #5
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answered by micahcf 3
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2y² - 3y - 1 = 0
y = [3 ± â(9 + 8)] / 4
y = [3 ± â17] / 4
y = 0.75 ± 1.03
y = 1.78, - 0 .28
2007-03-29 13:41:20
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answer #6
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answered by Como 7
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move the one to the other side and factor so you have two smaller equations of something times y plus or minus something, then you set both of those equal to 0 and solve for y, you should have 2 different answers for y, put them both down as y = __ or __
2007-03-29 13:02:46
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answer #7
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answered by Anonymous
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Move the 1 over to the other side and factor.
2007-03-29 13:00:05
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answer #8
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answered by leaptad 6
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2y^2-3y=1
2y^2-3y-1=0
(2y+1)(y-1)
y=1/2 (or) y=1
PcD
2007-03-29 13:13:59
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answer #9
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answered by shalu 3
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hehe no.
2007-03-29 13:08:25
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answer #10
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answered by Will H 2
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