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Solve the following equation by completing the square. 4x2 -16 x + 8=0 ​

1 Answer

3 votes

Answer:

x = 2±sqrt(2)

Explanation:

4x^2 -16 x + 8=0

Move the 8 to the right side by subtracting 8 from each side

4x^2 -16 x + 8-8=0-8

4x^2 -16 x =- 8

Get the x^2 term to have a coefficient of 1 by dividing each term by 4

x^2 -4x = -2

Take the coefficient of x and divide by 2 and then square it

-4/2 = -2

(-2 )^2 = 4

Add this to each side

x^2 - 4x +4 = -2 +4

Factor the right side into ( x +b/2)^2 where b is the coefficient of x

(x-2)^2 = 2

Take the square root of each side

x-2 = ±sqrt(2)

Add 2 to each side

x = 2±sqrt(2)

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