def vector_sum(vector1, vector2, coeff=1.0):
    """ Sums the vectors.

    This function computes the result of the vector operation :math:`\\overline{v}_{1} + c * \\overline{v}_{2}`, where
    :math:`\\overline{v}_{1}` is ``vector1``, :math:`\\overline{v}_{2}`  is ``vector2`` and :math:`c` is ``coeff``.

    :param vector1: vector 1
    :type vector1: list, tuple
    :param vector2: vector 2
    :type vector2: list, tuple
    :param coeff: multiplier for vector 2
    :type coeff: float
    :return: updated vector
    :rtype: list
    """
    summed_vector = [v1 + (coeff * v2) for v1, v2 in zip(vector1, vector2)]
    return summed_vector