Question

Срооочно! Плачу 40 баллов!
(х²- х - 1 )² - 10(х² - х - 1) + 9 = 0
Через дискриминант и замену!

Answer 1

производим замену: х^2-х-1= у
${y}^{2} - 10y + 9 = 0 \ d = 100 - 36 = 64 \ y1 = frac{10 - 8}{2} = 1 \ y2 = frac{10 + 8}{2} = 9 \ {x}^{2} - x - 1 = 1 \ {x }^{2} - x - 2 = 0 \ x1 = 2 \ x2 = - 1 \ {x}^{2} - x - 1 = 9 \ {x}^{2} - x - 10 = 0 \ x3 = frac{1 - sqrt{41} }{2} \ x4 = frac{1 + sqrt{41} }{2}$