(2z²+11z)²-23(2z²+11z)+126=0
2z²+11z=v
v²-23v+126=0 D=25
v₁=9 v₂=14
2z²+11z=9 2z²+11z-9=0 D=193 x₁=(-11+√193)/4 x₂=(-11-√193)/4
2z²+11z=14 2z²+11x-14=0 D=233 x₃=(-11+√233)/4 x₄=(-11-√233)/4.
X³ + (m - 1)x + m = 0
x(x² + m - 1) + m = 0
x(x² - 1) + m(x + 1) = 0
x(x - 1)(x + 1) + m(x + 1) = 0
(x + 1)(x(x - 1) + m) = 0 x = -1
x² - x + m = 0 D = b²-4ac = 1-4m
x₁ = (1+√(1-4m))/2
x₂ = (1-√(1-4m))/2
Ответ: {-1; (1+√(1-4m))/2; (1-√(1-4m))/2}
√5 + √10 - √20 + √121;
√121 = 11;
-√20 = -2√5;
(1-2)√5 = -√5; (выносим за скобку √5)
-√5 + √10 +11 = 11.92621
Мало балов за такую работу даешь...