Вопрос пользователя:
x^3+x^2-9x-9=0 ; 2x^3+8x=x^2+4 ; 3x^3 – x^2 + 18x-6=0
Илюха отвечает:
x^3 + x^2 – 9x – 9 = 0
x^2 (x + 1) – 9(x + 1) = 0
(x^2 – 9)(x + 1) = 0
x + 1 = 0
x₁ = – 1
x^2 – 9 = 0
x^2 = 9
x₂ = – 3
x₃ = 3
—————————-
2x^3 + 8x – x^2 – 4 = 0
2x (x^2 + 4) – 1(x^2 + 4) = 0
(x^2 + 4)(2x – 1) = 0
x^2 + 4 = 0
x^2 = – 4
==> ∅
2x – 1 = 0
2x = 1
x = 0,5
—————————————-
3x^3 – x^2 + 18x – 6 = 0
x^2 (3x – 1) + 6(3x – 1) = 0
(3x – 1)(x^2 + 6) = 0
x^2 + 6 = 0
x^2 = – 6
x ==> ∅
3x – 1 = 0
3x = 1
x = 1/3