............................................
16
---
26
1/(x-2)(x+2)-1/(x-2)-1/(x+2)=(1-(x+2)-(x-2))/(x-2)(x+2)=
1-x-2-x+2/x^2-4=
1-2x/x^2-4
256+b^4+b^2-32b^2-32b+2b^3
256+b^4-31b^2-32b+2b^3
b^4+2b^3-31b^2-32b+256
6-3х-2х-х^2=х^2-5х+2х-10
-3х-2х-х^2-х^2+5х-2х=-10-6
-2x=-16
x=8
по-моему так!