Dựa vào quy tắc phép chia ta có:
P(x)=Q(x)×S(x)+R(x) hay P(x)−R(x)=Q(x)×S(x).
Suy ra Q(x)=[P(x)−R(x)]/S(x)=[3x3−2x2+5)−(3x+3)]/(3x−2)
=(3x3−2x2−3x+2)/(3x−2)=x2−1