Question

Arata ca (x-5) la puterea 3 -x+5=(x-4)(x-5)(x-6), pt orice nr real x

Answer 1

                                                                
S-ar putea deoarece x∈N  ⇒ X=5+5-4+6=12÷4=3⇒X=nr impar ∉0

Answer 2

( x - 5 )³ - x + 5 =
= ( x - 5 ) ( x - 5 ) ( x - 5 ) - x + 5
= ( x² - 5x - 5x + 25 ) ( x - 5 ) - x + 5
= x³ - 5x² -5x² + 25x - 5x² + 25x + 25x - 125 - x + 5
= x³ - 15x² + 75x - 125 - x + 5
= x³ - 15x² + 74x - 120

( x - 4 ) ( x - 5 ) ( x - 6 )
= ( x² - 5x -4x + 20 ) ( x - 6 )
= x³- 6x² - 5x² + 30x - 4x² + 24x + 20x - 120
= x³ - 15x² + 74 x - 120

x³ - 15x² + 74x - 120 = x³ - 15x² + 74x - 120