Thực hiện phép tính 1/x-1-x^3-x/x^2+1.(1/x^2-2x+1+1/1-x^2)
Giải thích
1x−1−x3−xx2+1.1x2−2x+1+11−x2DK:x≠±1
=1x−1−xx+1x−1x2+1.1x−12−1x+1x−1
=1x−1−xx+1x−1x2+1.x+1x+1x−12−x−1x+1x−12
=1x−1−xx+1x−1x2+1.x+1−x+1x+1x−12
=1x−1−xx+1x−1x2+1.2x+1x−12
=1x−1−2xx2+1x−1
=x2+1−2xx2+1x−1
=x−12x2+1x−1=x−1x2+1