Решите уравнение: x^3 +x^2=9x+9

Question

Решите уравнение: x^3 +x^2=9x+9

Answer 1

X^3+x^2-9x-9=0
x^2(x-1)-9(x-1)=0
(x^2-9)(x-1)=0
x=-3;3;1

Answer 2

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 

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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
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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