d. (x+1)(x^2 - x + 1) - x^2 - x > 0

d)x+1x2−x+1−x2−x>0⇔x+1x2−x+1−x(x+1)>0⇔x+1x2−x+1−x>0⇔x+1x−12>0⇔x+1>0⇔x>1

Vậy x > 1