def amdahls(x, p):
    """
    Computes Amdal's Law speed-up
    :param x: is the speedup of the part of the task that benefits from improved system resources
    :param p: is the proportion of execution time that the part benefiting from improved resources originally occupied
    :return: the computed speed-up
    """
    return 1. / (1. - p + p/x)