b) A(x) = – 12x^5 + 2x^3 – 2, B(x) = 9 – 2x – 11x^2 + 2x^3 – 11x^5.

b) Với A(x) = –12x⁵ + 2x³ – 2, B(x) = 9 – 2x – 11x² + 2x³ – 11x⁵ ta có:

C(x) = (– 12x⁵ + 2x³ – 2) – (9 – 2x – 11x² + 2x³ – 11x⁵)

         = – 12x⁵ + 2x³ – 2 – 9 + 2x + 11x² – 2x³ + 11x⁵

         = (– 12x⁵ + 11x⁵) + (2x³ – 2x³) + 11x² + 2x – 2 – 9

         = – x⁵ + 11x² + 2x – 11.