Решите уравнение (5 х+6) ^4 + 5 (5 х+6) ^2-6 = 0

(5 х+6) ²=у

у²+5 у-6=0

D=25+4*6=49 (+-7²)

у1 = (-5-7) / 2 = - 6

у2 = (-5+7) / 2=1

(5x+6) ² = - 6

25x²+60x+36+6=0

25x²+60x+30=0

5x²+12x+6=0

D/4 = (-6) ² - 5*6 = 6 = (≈ ±2.45)

x1 = (-6+2.45) / 5 = - 0.71

x2 = (-6-2.45) / 5 = - 1.69

(5x+6) ²=1

25x²+60x+36-1=0

25x²+60x+35=0

5x²+12x+7=0

D/4=36-35=1

x3 = (-6+1) / 5 = - 1

x4 = (-6-1) / 5 = - 1.4