Thực hiện phép tính: (x – 1)(x + 1)(x + 2)
Giải thích
(x – 1)(x + 1)(x + 2)
= (x2 + x – x – 1)(x + 2)
= (x2 – 1)(x + 2)
= x2( x + 2) – 1.(x +2)
= x3 + 2x2 – x – 2
(x – 1)(x + 1)(x + 2)
= (x2 + x – x – 1)(x + 2)
= (x2 – 1)(x + 2)
= x2( x + 2) – 1.(x +2)
= x3 + 2x2 – x – 2