2x^-x-1=0 dengan cara melengkapkab kuadrat sempurna

Persamaan Kuadrat

2x²- x – 1 = 0
x² – (1/2)x – (1/2) = 0
x² – (1/2)x = (1/2)
x² – (1/2)x + (1/16) = (1/2) + (1/16)
(x – 1/4)² = (9/16)
x – 1/4 = ± √(9/16)
x – 1/4 = 3/4 atau -3/4

x – 1/4 = 3/4
x = 3/4 + 1/4
x = 1

x -1/4 = -3/4
x = -2/4
x = -1/2