Whenever the governing board of a school district maintaining an adult school or classes for adults is unable to maintain the school or classes in the school district because of its inability to secure a teacher or teachers, or because of lack of facilities, the governing board of the school district may, with the approval of the county superintendent of schools and the Superintendent, maintain the school or classes of the school district elsewhere than within the school district or contract for instruction of the students in an adult school or classes with the governing board of another school district.