Cách 1 : `f(x) = x^3 + 2x^2 – x^2 + 4 = (x^3+ 2x^2) – (x^2 – 4) = x^2(x + 2) – (x – 2)(x + 2)`
` = (x + 2)(x^2 – x + 2).`
Cách 2 :` f(x) = (x^3+ 8) + (x^2– 4) = (x + 2)(x^2 – 2x + 4) + (x – 2)(x + 2)`
` = (x + 2)(x^2 – x + 2).`
Cách 3 : `f(x) = (x^3 + 4x^2 + 4x) – (3x^2 + 6x) + (2x + 4)`
`= x(x + 2)^2– 3x(x + 2) + 2(x + 2) = (x + 2)(x^2 – x + 2).`
Cách 4 : `f(x) = (x^3 – x^2 + 2x) + (2x^2 – 2x + 4) = x(x^2– x + 2) + 2(x^2 – x + 2)`
` = (x + 2)(x^2– x + 2).`
#xin-hay-nhất!!!!!