Thực hiện phép tính 1/x+1-1/x^3+1+1/x^2-x+1

1x+1−1x3+1+1x2−x+1=1x+1−1x+1x2−x+1+1x2−x+1=x2−x+1−1+x+1x+1x2−x+1=x2+1x+1x2−x+1