# 添加一步检查参数，如果不是参数或者浮点型参数，就报错

    if not isinstance(a,(int,float)) or not isinstance(b,(int,float)) or not isinstance(c,(int,float) ):

        raise TypeError("bad operand type")

    dart = b**2 - 4*a*c

    if a==0:

        print("此方程无意义")

    elif dart < 0:

        print("此方程无解")

    elif dart == 0:

        x = -b/(2*a)

        print(f'此方程的解为：x1=x2={x:.1f}')

        return x

    else:

        x1 = (-b + math.sqrt(dart))/(2*a)

        x2 = (-b - math.sqrt(dart))/(2*a)

        print(f'此方程的解为：x1={x1:.1f},x2={x2:.1f}')

        return x1,x2