SOLUTION: Please solve: 4x^2+8x-4=0

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Question 217300: Please solve:
4x^2+8x-4=0
Found 2 solutions by chibisan, stanbon:
Answer by chibisan(131) About Me  (Show Source):
You can put this solution on YOUR website!
it would be easier to take our the common factor first to make the equation smaller .
4(x^2 + 2x - 1) = 0
x^2 + 2x - 1 = 0
by using this formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
subt in the values of a , b and c
x+=+%28-2+%2B-+sqrt%28+%282%29%5E2-4%2A%281%29%2A%28-1%29+%29%29%2F%282%2A%281%29%29+
x+=+%28-2+%2B-+sqrt%28+4+%2B+4+%29%29%2F%28+2+%29+
x+=+%28-2+%2B-+sqrt%28+8+%29%29%2F%282%29+
x = -2 + sqrt 8 / 2 or -2 - sqrt 8 / 2
x = 0.41 or x = -2.41 (3 s.f)

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
4x^2+8x-4=0
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4(x^2 + 2x - 1) = 0
x^2 + 2x -1 = 0
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Quadratic Formula:
x = [-2 +- sqrt(4-4*1*-1)]/2
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x = [-2 +- sqrt(8)]/2
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x = [-2 +- 2sqrt(2)]/2
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x = [-1 +-sqrt(2)]
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Cheers,
Stan H.