2$x^{4}$ - 9x³ + 14x² - 9x + 2 = 0
<=> 2$x^{4}$ - 4x³ + 2x² - 5x³ + 10x² - 5x + 2x² - 4x + 2 = 0
<=> 2x²(x² - 2x + 1) - 5x(x² - 2x + 1) + 2(x² - 2x + 1) = 0
<=> ( 2x² - 5x + 2)(x² - 2x + 1) = 0
<=> (2x² - x - 4x + 2)(x-1)²=0
<=> [x(2x-1) - 2(2x-1)](x-1)² = 0
<=>(x-2)(2x-1)(x-1)² = 0
TH1: x-2 = 0 <=> x =2
TH2: 2x-1 = 0 <=> x = 1/2
TH3: x-1 = 0 <=> x = 1