X²+2x+1=(x+1)²
(x²/(x+1)²) - (x-1)/(x+1)=
=(x²-(x-1)(x+1))/(x+1)²=
=(x²-x²+1)/(x+1)²=1/(x+1)²=
=1/(19+1)²=1/20²=1/400=
=0.0025
.................................... на фото
Раскроем скобки
2х^2 + 2 - 4x = 0
D = 16 - 4 * 2 * 2 = 16-16 = 0
x1,2 = 4 +- 0/4
х1 = 1
х2 = 1
Ответ: 1