b) Tìm đa thức K(x) sao cho K(x) – G(x) = F(x).
Giải thích
b) Ta có K(x) – G(x) = F(x).
Suy ra K(x) = F(x) + G(x)
Hay K(x) = (2x4 – x3 + x – 3) + (– x3 + 5x2 + 4x + 2)
= 2x4 – x3 + x – 3 – x3 + 5x2 + 4x + 2
= 2x4 + (– x3 – x3) + 5x2 + (x + 4x) + (– 3 + 2)
= 2x4 – 2x3 + 5x2 + 5x – 1.
Vậy K(x) = 2x4 – 2x3 + 5x2 + 5x – 1.