Upon resolution adopted by its board of directors, an association may enter into all necessary and proper contracts or arrangements with any other cooperative corporation, association, or associations, formed in this or in any other state, for the cooperative and more economical carrying on of its business or any part thereof. Any two or more associations may, by an agreement, unite in employing and using or may separately employ and use the same personnel, methods, means, and agencies for carrying on and conducting their respective businesses.