Phân tích đa thức thành nhân tử bằng phương pháp tách: a) x^2 – x – 2; b) x^2 + x – 2.
Giải thích
a) x2 – x – 2
= x2 + x – 2x – 2
= x(x + 1) – 2(x + 1)
= (x + 1)(x – 2).
b) x2 + x – 2
= x2 – x + 2x – 2
= x(x – 1) + 2(x – 1)
= (x – 1)(x + 2).
a) x2 – x – 2
= x2 + x – 2x – 2
= x(x + 1) – 2(x + 1)
= (x + 1)(x – 2).
b) x2 + x – 2
= x2 – x + 2x – 2
= x(x – 1) + 2(x – 1)
= (x – 1)(x + 2).