import math


def quadratic(a, b, c):
    if a != 0:
        if b * b - 4 * a * c > 0:
            """ 有解 """
            x1 = (-b + math.sqrt(b * b - 4 * a * c)) / 2 * a
            x2 = (-b - math.sqrt(b * b - 4 * a * c)) / 2 * a
            return x1, x2
        elif b * b - 4 * a * c == 0:
            return (-b + math.sqrt(b * b - 4 * a * c)) / 2 * a
        else:
            """ 无解 """
            return "该方程无解"
    else:
        return "二元一次方程a不能等于0"


a = int(input('请输入数字a:'))
b = int(input('请输入数字b:'))
c = int(input('请输入数字c:'))
result = quadratic(a, b, c)
if isinstance(result, float):
    print('方程%dx*x+%dx+%d=0的解是:x=%.2f' % (a, b, c, result))
elif len(result) == 2:
    print('方程%dx*x+%dx+%d=0的解是:x1=%.2f,x2=%.2f' % (a, b, c, result[0], result[1]))
else:
    print(result)