Project Euler 44

def isPent(n):
    a = 3
    b = 1
    c = -2 * n
    d = (b ** 2) - (4 * a * c)
    answer = (-b - (d ** 0.5)) / (2 * a)
    if str(abs(answer))[-1] == '0':
        return True
    else:
        return False

def penta(n):
    numb = []
    for x in range(1, n + 1, 1):
        pent = int(x * ((3 * x) - 1) / 2)
        numb.append(pent)
    return numb

def PE44():
    possibles = penta(10000)
    answers = []
    for x in possibles:
        for y in possibles:
            if isPent(x + y) and isPent(x - y):
                answers.append(abs(x - y))
    return answers

PE44()