Ответ:

1.x1 = 2, x2 = -2, x3 = -√2 х4 = √2

2.=

3.

Объяснение:

x^4 - 6x^2 + 8 = 0

x^2 = y

y^2 - 6y + 8 = 0

D = (-6)^2 - 4(1 * 8) = 36 - 32 = 4

y1 = -(-6) - √4 / 2 * 1 = 6-2 / 2 = 4/2 = 2

y2 = -(-6)+√4/2*1 = 6+2/2 = 8/2 = 4

x^2 = y

x1 = √2

x2 = -√2

x3 = -2

x4 = 2

2. 6x^2+13x-5/3x-1

+13x-5=0

D=-4(6*(-5))=169+120=289=

===-2,5

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=(х- сокращается, и раскрываем скобки)