Tính (x^2 - 2x + 5) . (x - 2).
Giải thích
(x2 - 2x + 5) . (x - 2) = (x2 – 2x + 5) . x – (x2 – 2x + 5) . 2
= (x3 - 2x2 + 5x) – (2x2 – 4x + 10)
= x3 - 2x2 + 5x - 2x2 + 4x - 10
= x3 - 4x2 + 9x - 10
(x2 - 2x + 5) . (x - 2) = (x2 – 2x + 5) . x – (x2 – 2x + 5) . 2
= (x3 - 2x2 + 5x) – (2x2 – 4x + 10)
= x3 - 2x2 + 5x - 2x2 + 4x - 10
= x3 - 4x2 + 9x - 10