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27 votes
27 votes
Plss helppp!!

pls show how is it done

solve the equation :

x³ = 3x² + 3x - 1



User Arnaud BUBBLE
by
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1 Answer

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20 votes

Answer:

  • x³ = 3x² + 3x - 1
  • x³- 3x² - 3x + 1 = 0
  • (x³ + 1) - 3x(x + 1) = 0
  • (x + 1)(x² - x + 1 - 3x) = 0
  • (x + 1)(x² - 4x + 1) = 0
  • (x + 1)(x² -4x + 4 - 3) = 0
  • (x + 1)((x - 2)² - (√3)²) = 0
  • (x + 1)(x - 2 + √3)(x - 2 - √3) = 0
  • x = -1
  • x = 2 - √3
  • x = 2 + √3
User Brian McKenna
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