`D = (x^2 - 7)(x+2)-(2x-1)(x-14)+x(x^2-2x-22)+35`
`= x^3 + 2x^2 - 7x - 14 - (2x-1)(x-14)+x(x^2-2x-22)+35`
`= x^3 + 2x^2 - 7x - 14 - 2x^2 + 29x - 14 + x(x^2-2x-22)+35`
`= x^3 + 2x^2 - 7x - 14 - 2x^2 + 29x - 14 + x^3 - 2x^2 - 22x + 35`
`= 2x^3 - 2x^2 - 14 - 14 + 35`
`= 2x^3 - 2x^2 + 7`
Vậy `D = 2x^3 - 2x^2 + 7`