`#Sad`
`2)`
`x^3+6x^2+12x+8`
`= x^3+3. x^2. 2+3. x. 2^2+2^3`
`= (x+2)^3`
`⇒` `\text{Chọn B}`
`\text{→Áp dụng:}` `(A+B)^3 = A^3+3A^2B+3AB^2+B^3`
`3)`
`x^3-6x^2+12x-7`
`= x^3-6x^2+12x-8+1`
`= (x^3-6x^2+12x-8)+1`
`= (x^3-3. x^2. 2+3. x. 2^2-2^3)+1`
`= (x-2)^3+1`
`\text{→Thay}` `x=32` `\text{vào ta có:}`
`= (32-2)^3+1`
`= 27000+1`
`= 27001`
`⇒` `\text{Chọn C}`
`\text{→Áp dụng:}` `(A-B)^3 = A^3-3A^2B+3AB^2-B^3`
