The polynomial −2x3 − x2 + 13x in the last line is the result of


dividing x2 + 3x + 1 by 3x2 and bringing
down 13x.

subtracting 3x4 + 9x3 + 3x2 from the
dividend and bringing down 13x .

multiplying 3x2 by x2 + 3x + 1.