def Z_7_func(*, C, Z_1, Z_2, Z_3, Z_4, a_0, v_φ, ρ):
    """
    Compute the value of the variable Z_7
    """
    return Z_2 + (C + Z_3) * (Z_1 * v_φ ** 2 * ρ - Z_2 * Z_4) / (v_φ ** 2 *
        ρ + 2 * a_0 * Z_3 * Z_4)
