25x^2 - 10x + 1 - (25x^2 + 10x + 1) = 16x^2 + 8x + 1 + 16x^2 - 8x + 1
25x^2 - 10x + 1 - 25x^2 - 10x - 1 = 16x^2 + 8x + 1 + 16x^2 - 8x + 1
- 20x = 32x^2 + 2
32x^2 + 20x + 2 = 0 /:2
16x^2 + 10x + 1 = 0
D = 36
x1 = ( - 10 + 6)/32 = - 0,125
x2 = ( - 10 - 6)/32 = - 0,5