The boards of directors of two or more school districts may by agreement provide for attendance of pupils residing in one district in the schools of another district for the purpose of taking courses not offered in the district of their residence. The boards may also provide by agreement that the districts will combine their enrollments for one or more grades. Courses and grades made available to students in this manner shall be considered as complying with any standards or laws requiring the offering of such courses and grades. The boards of directors of districts entering into such agreements may provide for sharing the costs and expenses of the courses. If the agreement provides for whole grade sharing, the costs and expenses shall be paid as provided in sections 282.10 through 282.12.