Question

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Answer 1

-27 = x4 – 12x2
x4 – 12x2 + 27 = 0
y = x^2

y^2 - 12y + 27 =0
(y - 9)(y - 3) =0
y = 9 ===> x = +3 or -3
y = 3 ===> x = sqrt(3) or - sqrt(3)

Answer 2

Sweet THX :)

Answer 3

If decimals needed 1.7321 or - 1.7321

Answer 4

Thx :)