Răspuns :
(x²-x+1)²=x⁴-2x³+3x²-2x+1
(x²-x)²+2(x²-x)•1+1=x⁴-2x³+3x²-2x+1
(x²-x)²+2x²-2x=x⁴-2x³+3x²-2x
x²+2x²=3x²
3x²=3x²
0=0
x aparține R
Ծ ̮ Ծ
(x²-x)²+2(x²-x)•1+1=x⁴-2x³+3x²-2x+1
(x²-x)²+2x²-2x=x⁴-2x³+3x²-2x
x²+2x²=3x²
3x²=3x²
0=0
x aparține R
Ծ ̮ Ծ
(a - b + c)² = a² + b² + c² - 2ab - 2bc + 2ca
(x² - x + 1)² = x⁴ +x² +1² - 2·x²·x - 2·x·1 + 2·1·x² =
= x⁴ + x² + 1 - 2x³ - 2x + 2x ² = x⁴ - 2x³ + 3x² - 2x +1.