Ta có: A(x) - C(x) = B(x), suy ra C(x) = A(x) - B(x)
a) C(x)=(x3+x2+x−2)−(9−2x+11x3+x4)
= x3+x2+x−2−9+2x−11x3−x4=−x4−10x3+x2+3x−11
b) C(x)=(−12x5+2x3−2)−(9−2x−11x2+2x3−11x5)
= −12x5+2x3−2−9+2x+11x2−2x3+11x5=−x5+11x2+2x−11