long division- polynomials

[kpx001]

x+1; x^3-21x-20

...........x^2-2x-19
x+1 / x^3-0x^2-21x-20
....../-x^3+x^2
...............-2x^2-21x
...............--2x^2-2x
..........................-19x-20
..........................--19x-19
....................................1

right here im confused. answer is
(x-5)(x+4) in factored form so dunno what im doing wrong. i think its with x^2 or something. i figured it out it was the 0x^2 + x^2. i need verification if its -x^2 or +x^2 because when adding place holders, is it +0x^2 or -x^2

 

[skeeter]

x+1; x^3-21x-20

...........x^2-2x-19
x+1 / x^3-0x^2-21x-20
....../-x^3+x^2
...............-2x^2-21x mistake is here ... should be -x^2 - 21x - 20
...............--2x^2-2x
..........................-19x-20
..........................--19x-19
....................................1

right here im confused. answer is
(x-5)(x+4) in factored form so dunno what im doing wrong. i think its with x^2 or something. i figured it out it was the 0x^2 + x^2. i need verification if its -x^2 or +x^2 because when adding place holders, is it +0x^2 or -x^2

 

[Gene]

It should go
(x^3-21x-20)/(x+1)

            x^2  -1x -20
x+1 / x^3 -0x^2 -21x -20
      x^3 +1x^2
          -1x^2 -21x
          -1x^2  -1x
                -20x -20
                -20x -20
                       0

(x+1)(x-5)(x+4)

Skeeter types faster than I do, but I clicked on the C... (code) button.