I didn't feel like calculating my math homework by hand (I mean with a calculator but still) so I made python do it for me.

example.txt

: -3,0,3,0,0,0,9
b: 1,-1
[-3.0, -3.0, 0.0, 0.0, 0.0, 0.0]
[9.0]

polynomial_div.py

a = input("a: ")
a = list(map(lambda i: float(i),a.split(",")))

b = input("b: ")
b = list(map(lambda i: float(i),b.split(",")))

d_len = len(a) - len(b)

o = [0] * (d_len + 1)

for i in range(d_len+1):
    m = a[i] / b[0]
    for j,v in enumerate(b[1:]):
        a[i+j+1] -= v * m
    o[i] = m
    a[i] -= m

print(o)
print(a[-(len(b)-1):])